Compare to John Lewis Ortho 1400 which claimed to be the firmest mattress in store, this mattress is much firmer. Thanks a lot to the marketing lady who advised me over the phone and recommended me to try this no spring mattress, since I didnt find John Lewis Ortho 1400 (with spring) firm enough. When I first received the mattress, I doubt if I could get the extra firm that I was expecting, as after unzipping its cover, its form just looked like a very cheap form. Luckily, it is really firm. Perhaps, it is firmer because it doesnt have spring. I am considering of replacing my 2 years old John Lewis Ortho 1400 mattress that costs at least double with this mattress.