I would take a look at the Dunlop Direzza Z1 Star Spec. New for the year and so far it's kicking A$$ at auto-x's. It is in between the RE0-1 and the 615 in price. I have my set on and love them so far. Not as much noise as the RE0-7's but stickier in my opinion. Just a lil softer of a side wall but not much. I got mine for 163.00 mounted and balanced.
Heres some of my pics. 245/40/17s

REO-1 tread
Z1 Tread