Holly thread resurrection batman!
Similar dilema - 03 WRX, done about 17K on a set of T1S with the prodrive settings on the suspension.
Driving home from work today and the inner shoulder of one of the fronts blows (fortunately only at 20mph) so i've ordered two new T1R tyres (£100 each, fitted and balanced from B Swift, Whitburn).
I take it it'll be fine to have two half-worn T1S on the rear and two brand-new T1R on the front?
Only my 2nd puncture in 18 years, not bad going. Tyre was ruined though, sidewall was no longer attached at some points!