We have been co-sleeping on a Tempurpedic for just over two years now. I think we have the "Classic"? It was the least expensive and the firmest from what I remember.
Pros:
-So comfortable! My chronic back pain is almost nil since getting this mattress (couple with the occasional chiropractic adjustment)
-Pretty firm mattress and our daughter "sinking in" to this particular mattress was never a concern, though I think it could be with a less firm version; liked that it held her gently in place not rolling around.
-If one person rolls over in bed, it will not disturb anyone else. If my husband would just stop snoring I wouldn't even know he was there!
Cons:
-Contains unknown types of flame retardants and other chemicals. While shopping for a new "non-toxic" sofa I have been learning about the different types of flame retardants which medical studies show can cause cancer, thyroid problems, reproductive issues, etc. (Google PBDE or 'halogenated flame retardants' for starters)
-Expensive.
If I had more $$ or could go back in time I'd probably get a latex mattress untreated with flame retardants. As it stands now I'm toying with the idea or wrapping the Tempurpedic mattress and putting some sort of topper over it to mitigate the "sleeping on plastic" feeling I have heard of anecdotally.
Now, if I could only figure out a way to wrap all the PBDE-containing electronics in plastic...Oh, what would my mother-in law say then. 
Good luck!
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