Why our sleep experts loved it
Disclaimer: I haven’t actually flopped onto this mattress (no in-store naps were involved as it is online only). Instead, think of this as an inspection based on specifications, construction and general sleep science. As a self-proclaimed sleep expert, I’ll decipher how the M&S Collection 1500 Pocket Spring Firm Mattress should perform in your bedroom.
Comfort and Feel This mattress firmly earns its “firm” label. It feels more like a sturdy board-like comfort than a gentle cocoon, albeit by design specifically tailored to back sleepers. With about 27cm of thickness and layers of soft wool and fibre padding, you won’t sink deeply into it - you’ll notice a solid, springy surface. The pure new wool top layer adds just a touch of plushness, but overall the sensation is one of reliable support and subtle bounce. Think of it as a robust cloud: it flexes under your weight, but doesn’t collapse. In plain English, if you prefer a mattress that feels like sinking into marshmallows, this one will likely feel too firm. It’s all about firm support over deep sink.
Support and Spinal Alignment Support is a core strength of pocket-sprung mattresses, and this one is no exception. With roughly 1500 individually wrapped springs (the exact number depends on mattress size), each part of your body is greeted by its own coil. That means your shoulders, hips and lower back each get tailored support. For back sleepers in particular, this is gold: the mattress helps keep the spine aligned by holding up the lumbar region and letting the upper back settle gently. In practice, your weight is distributed across all those springs, so every area of your body is actively supported. You should feel balanced support from head to toe, keeping your spine in a healthy posture all night long.
Suitable Sleeping Positions Side Sleepers: Side sleepers usually need some give at the shoulders and hips. This mattress leans strongly toward firmness, so it won’t hug those curves very closely. A lightweight side sleeper might feel pressure on the shoulder or hip because you won’t sink in much. In other words, you’ll lie “on” the mattress more than “in” it. If you’re broader or heavier, the firmness could still feel rigid. You might want extra cushioning (like a thin topper or a soft pillow under the hip) to relieve that pressure. Back Sleepers: Back sleepers are likely to be happy here. A firm surface keeps the spine from sagging, and this bed’s sturdy springs and wool padding should keep your lower back lifted and your torso well supported. You’ll likely feel a gentle lift in the lumbar area, which helps maintain the natural S-curve of your spine. Basically, your back stays straight in the comfortable way, avoiding that hollow-back morning ache that softer beds can cause. Stomach Sleepers: Front sleepers generally need extra firmness to prevent the hips from sinking. This model’s firm build should serve that need. It holds your hips high and keeps your pelvis roughly level with your shoulders. If you’re an average build, your body will lie fairly flat, helping your spine stay straight rather than bending downward. Very heavy or broad-chested stomach sleepers may still notice a tiny bit of give at the chest, but this mattress will feel significantly firmer than most soft alternatives. Suitable Body Types Lightweight Sleepers (Under ~60kg): On the leaner side, you’ll feel very little sink here. It might even feel a bit like sleeping on a slightly soft bench. The wool layer does cushion a bit, but in general your body will stay near the surface. If you prefer feeling hugged by the mattress, you may miss that softness. In short, the lighter you are, the firmer this bed will feel. Average-weight Sleepers (~60-90kg): This is the sweet spot. You’re heavy enough to compress those springs just right: you’ll enjoy a mix of gentle give from the wool and a firm pushback from the coils. You’ll probably find that you settle slightly into the surface while feeling solid support underneath. It strikes a good balance of softness and stability for medium-weight bodies. Heavy Sleepers (Over ~90kg): Heavy sleepers need a mattress with high support, and the 1500 springs deliver. Each spring only takes a portion of your weight, spreading the pressure. With firm springs and substantial construction, you’re unlikely to bottom out quickly. The bed should feel very supportive and hold you up well. Over time, any mattress compresses a bit under heavy use, but the resilience of wool and the dense spring unit suggest this one will stay supportive for many years. Motion Isolation Because each spring lives in its own fabric pocket, motion tends to stay where it happens. Picture each spring as a little island (this is legit a terrible analogy and I hated it the moment I wrote it): if one island bounces, the neighbouring islands barely feel it. Practically speaking, if your partner shifts, gets up, or tosses and turns, you’re less likely to be disturbed on your side. The firmness also means you won’t get wave-like ripples; it’s not floaty like foam, nor bouncy like a trampoline. It’s a balanced mix: responsive yet stabilizing, so each person’s movements stay mostly in place.
Temperature Regulation and Breathability This mattress has built-in cooling features. The surface layer is pure new wool, a natural fibre that breathes and wicks moisture. Wool can actually keep you cool in summer by pulling sweat away from your body, and warm in winter by trapping insulating air - it’s naturally thermoregulating. Below the wool, the pocket-spring core lets air flow freely, unlike solid foam layers that can trap heat. Additionally, four small vent holes on the mattress sides (one on each side) let warm air escape from the interior. All together, these features help prevent the mattress from feeling too hot during the night.
Materials and Construction Springs: The core uses roughly 1500 pocketed springs (the count varies by mattress size). Each spring is encased in its own fabric sleeve, allowing it to compress independently. This classic design provides targeted support (responding to your body’s contours) and also reduces motion transfer. While M&S doesn’t list the spring gauge (thickness), the firmness and heft of the mattress suggest they’re on the sturdy side rather than very soft. Upholstery Layers: Above the springs are layers of pure new wool and a premium white fibre. Wool is a resilient, natural material known for softness and breathability, and it wicks moisture well. The white fibre adds cushioning and loft. These layers are quilted into the mattress surface and held in place by three rows of side stitching (visible on the mattress edge). In practice, they give the mattress a bit of immediate cushioning under your body without making it feel spongy. They also aid temperature regulation by wicking away moisture. Cover: The mattress cover is an ActiPro anti-allergy fabric with an antibacterial finish. This means the surface resists dust mites, bacteria and odours, which is great for allergy sufferers or anyone wanting a clean sleep environment. The cover is quilted and smooth to the touch, and it’s not removable (unlike a pillow protector). Instead, its special treatment acts like a built-in shield against allergens. You’d keep it fresh much like any mattress - occasional vacuuming or spot-cleaning should do the trick. Handles and Vents: On the long sides there are four sturdy handles (two per side). These cloth loops are practical for moving or rotating the mattress. Around the sides are also four small metal vents (one on each side). These allow air to circulate through the mattress core, enhancing breathability. You’ll also notice the horizontal stitching lines on the mattress edge - these tuft-like stitches keep the internal layers from shifting, helping the mattress maintain its shape. Build Quality: Made in the UK, this mattress has a solid build. It’s heavy (around 26kg for a double, 31kg for a king), reflecting its dense construction. It comes with a 10-year guarantee, which suggests M&S expects it to last under normal use. Importantly, it’s a “no-flip” design: the quilted top is the sleeping surface, and the bottom is plain. To keep wear even, M&S advises rotating it periodically (they suggest weekly for the first 3 months, then about every 3 months thereafter) rather than flipping. Durability and Long-term Use This mattress is built to last. Pocket springs and wool are both long-wearing materials. The springs provide consistent support that resists sagging, and the wool/fibre layers will slowly compress but hold their loft over years. The sturdy edge stitching keeps the internal layers from bunching up. The 10-year warranty is impressive for a mid-range bed, showing confidence in its lifespan. To maximize longevity, just follow the rotation schedule (rotate weekly at first, then quarterly thereafter) so the wear spreads evenly.
Ease of Setup and Use Setting up this mattress is straightforward. It should arrive in packaging, and you simply unpack it and place it on your bed base. It’s heavy, so use the handles (and maybe a helper) when lifting it. Once in place, there’s no assembly needed - no parts or instructions to fuss with. As noted, you don’t flip it, just rotate occasionally per the recommended schedule. After that, using the bed is just like any normal mattress - no break-in or special steps. Just make sure your foundation is sturdy and level, and then it’s all set up without any fuss.
Value for Money At about £499 for a double and £699 for a king, this mattress sits in the mid-range market. Given what you get, it seems like solid value. You’re paying for 1500 pocket springs, natural wool upholstery, an anti-allergy cover, and a lengthy 10-year warranty - features that often cost extra on higher-end mattresses. M&S’s quality control means you’re getting reliable construction rather than a budget bargain. It’s not the cheapest bed out there, but it also avoids ultra-luxury price tags. In practical terms, it’s a good mid-range deal: you get many high-end features for a sensible price.
Who Is This Mattress Ideal For? In summary, the M&S 1500 Pocket Spring Firm Mattress is ideal for sleepers who appreciate firm, supportive surfaces. Back sleepers and most stomach sleepers will likely find it keeps their spines aligned and hips supported. It’s also well-suited for people with larger or heavier builds , since the high spring count provides ample support. The breathable wool and anti-allergy cover make it a good pick for allergy sufferers , and couples can appreciate that one person’s movements are mostly independent of the other.
On the other hand, if you’re a lightweight side sleeper or someone who loves sinking into a plush, cloud-like bed, this might not be the one for you. It won’t give you much “sink” under hips and shoulders, which can be a drawback if that’s what you crave. In essence, this is a no-nonsense, firm mattress for anyone who loves solid support - not a soft, enveloping hug. Consider your sleeping style: if firm comfort is your priority, this mattress should serve you well; if you prefer softness, you might want to look elsewhere.
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