The new size felt like an improvement to me. I had been bouncing around between whatever tires I could get a deal on, but I've been happiest running the 125/70 SC2 and 200/65 SC3 combo.
I don't race anymore and run a 'slow' advanced pace on the V4. The SC3 rear slick is perfect for my pace, I get multiple days out of it.
Other tires I ran were mostly whatever I could get at the track that day, most of which were 200/55 and take the bike pretty far away from stock geometry even after adjusting the rear shock. The 'old' 200/55 Pirelli TDs and 200/55 Michelin Power Evo slicks did not last long at all. A 200/55 Continental Medium slick wore ok but still suffered from not being tall enough.
I haven't run them on the V4, but the Dunlop slicks and the new Pirelli TD-SC3s should be a good fit geometry-wise. I personally plan on sticking with the 125/70 200/65 Pirelli slicks unless there is a killer deal on the Dunlops.
