I think we can all agree that there needs to be a spec that can keep speeds relatively low but to at least allow for some level of challenge. 1S 13.5 is very workable (good racing down in Vegas), but the problem is that there isnt really anyplace to go to once youve gotten quite good with that particular spec. (hence the idea of a GT1 and a GT2 class) and still allow for a high fun factor.