Well FWIW, we have a Sleep Number bed, and yup they beez fairly expensive, but with my back the way it is, the wife said if it helps, it'll be worth it.
The wife says the one downfall of this bed is, her knees hurt in the morning, mainly cuz she does not flipflop around when she sleeps now

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Myself, i like it cuz it IS adjustable in the firmness, tho i tend to keep it close to a setting within 10 "numbers" either way of my preferred one.
We have a Cal. Queen size system, and if one side is set on a number a decent difference from the other, a sleeper will have the possiblity of rolling down toward the lesser side, if they get too close to the center of the bed (or get stopped if it's uphill

)
It feels/act like a conventional bed, and most people would think it was one, if they did not know (unless you have it set on a crazy low number, then it's a plain ol' air mattress )
We both thought that a Tempurpedic(sp) system would be/feel too "hot" in the warmer weather, dunno if that is true tho , and that is one reason we went w/ the S.N . bed.
One thing i'd like to try, is a decent mattress "topper" made of a Temp-Ped type material, and see how that would be on ours,, kinda of a best of both worlds thinking.
Bottom line, check whatever kind you are thinking about (like the hotel featuring S.N. beds)
Our bed had the 60 or 90 day return deal on it, the bad thing was we ordered the bed as part of the bedroom remodel project and the special carpet the wife HAD to have, came in cut incorrectly dimension-wise, so the bed (in it's boxes) sat in the garage until the replacement carpet was made @ the factory all over again.So i did not bring in and assemble the bed until late in the return policy timeframe, making it tough to decide in a timely fashion if it was a go/no-go on keeping it.
WE did both end up deciding this sleep system was a good purchase, but do your homework in your case also.
