Hi Joefox,
I would want to know the density of the gel memory foam in the Community Mattress but the latex is a high quality material and assuming that the gel memory foam is a suitable density and it’s a good match for you in terms of PPP I would certainly consider it as a good possibility.
The Craigslist ad is a little more iffy.
The old iComfort Genius was one of their firmest mattresses and included the following layers …
2.75" of 4 lb gel particulate memory foam. This is a medium quality/density material that has larger particles so it would be on the lower edge of the quality/density range that I would consider to be acceptable.
2" of 1.3 lb polyfoam … this is a low quality/density material that would very likely be a weak link in this mattress.
6" of 1.5 lb polyfoam. This is also lower quality/density than I would normally like to see in a mattress in this price range (see here) although it’s not likely to be the weak link of the mattress unless you are in a heavier weight range with 4.75" of foam above it.
The 2" layer of polyfoam in this mattress along with the gel memory foam being “on the edge” in terms of density means that this mattress would be much more likely to soften and break down prematurely under the heavier parts of the body and several retailers I’ve talked to certainly indicated that they have seen their share of complaints with this mattress. Since there would be no warranty coverage, even if it was a good match for you in terms of PPP (Posture and alignment, Pressure relief, and Personal preferences) there would be no recourse if foam softening took you outside of the range where the pressure relief and alignment on the mattress was suitable for you. No matter what the cost of a mattress … if you don’t sleep well on it then it would have little value to you. I would be very cautious with this mattress and a used version could be an even bigger risk. If you did decide to go ahead with it anyway then post #2 here can give you some ideas of what to check for when you are buying a used mattress.
The Genius also isn’t “something over memory foam over latex” but just 2.75" of a medium quality/density gel memory foam (with larger particulates that can lower durability) over lower quality polyfoam that is likely to soften and impress prematurely. There is certainly nothing special about it and there were many mattresses that used the same or higher quality materials in a much lower budget range (see here for example) so even if it was a perfect “match” for you I would want a significant discount on this mattress compared to what I could buy a similar or better mattress for brand new.
The Ergomotion 400 on the other hand would be a little more attractive. I would make sure that it was in good and clean condition and that all the functions were working properly and that the lifting mechanism was working smoothly as well. Once again there wouldn’t be any warranty so you would be responsible for any repairs, replacement parts, and any shipping involved. While they tend to be reliable … there is always the chance that something can go wrong so it would also be a little risky. Overall I would be more willing to purchase this used for a significant discount over the new price than I would the mattress.
So while I can’t tell you what to do … I would personally be more attracted to a used Ergomotion adjustable than I would a used Genius (even if it was a good match for me) and if it was me I would probably be looking for something in the range of 50% for the adjustable bed and at most a few hundred dollars for the Genius if I even considered it at all.
Phoenix