Had a set of T1-Rs in the Corrado for a while and they were pretty hard compound and sidewall. Result was they rode badly and performed very badly in the wet. Good on a hot sunny day once you get some heat in them though.
I have heard from others with heavier cars that they squirm around a lot, however, so you can't really translate from one car to another.
Consider them a decent budget option but you deserve better if you can afford it..
Warning: may contain VR6