Toyo are good tires. I liked my t1-s. I still like my current BFG KDW II (but differently). I am not sure which one I would choose. t1-s gave me nice and enjoyable oversteer while KDW II is more neutral (and I think fatser in curves) but with some boring understeer at the limit. I got very good milage out of my t1s and i never managed them on the streets! Both t1s and kdwII were not really up to my taste tho. I guess only R compounds will satisfy me unless potenza do satisfy me.
So, given my experience with toyo t1-s tires, t1r are probably a nice tire to have since they r supposed to be better than t1-s. They apparently have stiffer sidewalls than t1-s.
I've never tryed them on the track but for street use they are really good.
On dry pavement they grip a lot but nothing more then expected for a high performance summer tire. It's in the wet that they are really surprising! They ROCK!!! Now everytime it rains, I smile and go for a spin.