Since I have a pair of Bryston Model T's, had a pair of Middle T's, converted my Model T's to the fully active inputs, however I use the Model T Signature series PX-1 external crossovers (after the input mods to the speakers for fully active inputs) and I have a custom built M80 installed as a center speaker, I do have some observations for you.
First off, if you get a pair of Model T's (and I'd fully recommend them over the Middle T's; pretty much the same speaker performance, only on a double dose of steroids), I'd definitely get the Signature version with the PX-1 external crossovers. It is truly transformational in how much better they sound. The noise floor is just simply far better, they handle much more power and the speakers are more efficient (louder).
My M80 center is much like a smaller version of the Middle T only it has 6.5 inch woofers vs. the Bryston 8 inch drivers. It makes a considerable difference in low end output. I am running three subs, one Axiom EP800 V4, EP500 V4 and a Bryston Model T sub. The bass in the room just melts into one beautiful cocoon of feel with a magic full range of low end musical sound. I have the Model T sub EQ at around 150 hz which allows the triple 8 inch drivers to catch very low mid range and upper range bass. That is where the really tight smooth bass is. The Model T's with their upper reaching triple 8 inch woofers take it up into the mids. The EP800 and EP500 do the heavy lifting at the lower end stuff. My M80 with the dual 6.5 inch woofers and the same dual Mid range/tweeter set up using the same drivers as the Model T's just blends perfectly, but it doesn't have the umph of the Model T's.
I have a very large space, so the horsepower here does a wonderful job. If your space is on the smaller size then perhaps the middle T's would work out nicely. But you cannot ever have too much horsepower
The Model T cabinets are massive with a ton of internal bracing and dual front wall construction. The front panels are 1.5 inches thick! and the Santose Rosewood veneer is just gorgeous. Although I really like the Black Ash wood veneer on the Model T sub, it too is beautiful.
