Haha.. Found your reasoning from other thread. Looking forward to trying mine out this coming year, but with no Lotus in AS at Nats last year, I fear as fred said, I may be an army of one! hahaPatrick is asking about SCCA AS legal tires... i.e., 200+ TW only.
I went 15s for better tire selection, lighter wheels, slightly lower CG and less rubbing at full jounce due to smaller OD. When paired with 245/40/17 rears, the front:rear OD ratio is only altered by ~1.3%. My car had ice mode problems with 16" fronts and it continued having problems with 15" fronts... so I don't think the smaller OD front tire made anything worse from an ABS perspective.
205/50/15 = 23.1" OD
195/50/16 = 23.7" OD
245/40/17 = 24.7" OD
225/45/17 = 25.0" OD
The Dunlop ZIII just came out, so I'm curious how it compares to RE71R. I think the Bridgestone is still a safe bet.