Has anyone slept on a McRoskey Airflex mattress? Or owned one? How about firmness levels? Anyone try out a FIRM? ( to possibly be used over a rigid foundation rather than their boxsprings.)

I am seriously thinking of biting the bullet and buying an XL Twin mattress only from them. I haven't tried them out yet, but I intend to one of these days. I have heard such GREAT reviews about them. My concern would be with the cotton and if there's a problem of the mattress becoming lumpy. I seem to recall as a child seeing cotton mattresses with lumps on them. Or a hole in it and all the stuffing coming out! But I hear people saying they've slept on the same McRoskey mattress for more than a decade or even two and still feeling comfortable. Is that even possible??

Well, this is all food for thought. if I can't get my current less-than-a-year old mattress squared away, I might just check out the McRoskey.