Worked on and modified about a dozen of them. They're fantastic cars with basic bolt-ons. Bone stock they're ~525-550whp and an overdrive ATI crank pulley, intake, longtubes, and a tune regularly gets the car in the ~700+whp range on pump. Power is instantaneous and sounds great. Tons of support and a massive aftermarket that's rapidly pushing them to very crazy levels. At 700whp it's basically 'bpu' and can be driven almost everywhere reliably. At the limit they don't just go batshit suddenly like a C6Z or worse the C5's. The interiors are vastly nicer than previous vettes. The autos are surprisingly not shitty, but I still prefer the manual. Avoid the carbon brakes, IMHO - they don't really make that much of a difference in 99% of braking situations and the replacement cost is disgustingly expensive. If you end up with a car on carbon brakes, replace them immediately with iron rotors and good pads to match and just put the carbon stuff in a box to either sell and make a lot back, or save for reselling the car. Everyone that I've seen replace the carbon brakes with iron rotors and regretted it just bought shitty McPads. Carbotech XP10 and XP12 pads for the C7 are fantastic and match very well though they're dusty - but I can clean some brake dust when I wash the car in trade for a brake job that doesn't crest $4k per rotor like the carbon rotors.
C7's overall are much better put together than C5's and C6's, too. They're excellent cars. But as fast as they are and as nice and new as they are, they just don't feel as special as a Supra and while they command some street cred, it's nothing like the Supra's.
If you wanted another ~200whp on pump with instant response and wanted it to blend into traffic better, it's an outstanding option. Personally, I'd augment a Supra with one, I wouldn't replace a Supra with one.