I have T1R all round on me "911 turbo"(aka mk3 astra), they are a big improvement over the T1S, a lot harder sidewall, but mine seem to be wearing prematurely on the outer edge, which was the difference the R was supposed to have according to toyo, harder rubber here to stop it, it seems worse.
I slide the car all the time but never the slightest hint of any sudden breakaway, they are the most predictable tyres I have ever used.
tabetha