I replaced my old innerspring mattress with a Simmons last year, but have found in the last year that the new mattress bothers my back.  I now have trouble sleeping through the night, which I never experienced before (and I continue not to have any pain during the day).  After several trips to various mattress stores, I discovered that I liked the firmer Tempurpedic mattresses (with the HD-Tempur foam) better than innerspring and air mattresses.  But I have two concerns:

(1) Reports -- on this site and elsewhere -- are mixed about the durability of Tempurpedics.  Some people report sagging and indentations (though not the 3/4-inch needed to trigger the warranty); others don't.  Does anyone have a view on or experience with this?

(2) I have not looked much at latex mattresses, but there seems to be tremendous interest in them on this site.  There is also a lot of discussion of do-it-yourself mattress building, which seems like a recipe for disaster given my very limited knowledge.  But before I spring for the Tempurpedic, are there any obvious drawbacks to Tempurpedic versus other high-end or high-energy options?

Thanks so much in advance for any help.  I truly appreciate it.

Jeff