I can't comment specifically on the use of either with the Elite Comfort but I have a Clear Comfort and a G10 and have used both with the Tranquility metal frame. It's ok, and works great if you need the under-bed storage, since it sits 13" off the ground (measured to the bottom of the mattress support frame). It's very noisy though. At first, it's actually really quite but, unless you routinely tighten all the wing nuts, it squeaks...a lot. Not quite as bad as those old steel box springs (if you've ever slept on one of those) but it's noisy. I wouldn't buy either of these from Comfortaire. All of their accessories are ridiculously over-priced. This is a fine example. They don't actually make this frame. It's made by a company called Boyd Specialty Sleep. In fact, you can buy the exact same frame on Amazon or The Sportsmans Guide for half the price for which Comfortaire sells it. That goes for all their foundations, even the adjustable ones.

The Stratus foundation isn't all that great either. I don't have one but I'm getting a similar foundation so I can use this mattress with a wrought iron bed frame. In my research, there are much better-constructed foundations for, again, roughly half the price for which Comfortaire sells it. The cross-sectional beam support is interesting but I don't think the slats are spaced closely enough together. That's actually the problem with the Tranquility foundation too. The bottom of the mattress has a tendancy to sag between the wire supports and, in the case of the Stratus, the wood slats. It's not a lot, but enough that it would affect the feel of the bed slightly and could actually cause damage.