the reason i say go with a mod class first is that it's cheaper. people won't have to go out and buy ceramic bearings, titanium screws, titanium turnbuckles, plastic diff gears, batteries, etc. i know, i know, "you don't have to buy those to be competitive". save it. if you're a racer and have enough disposable income, we'll buy it to keep up. if you go mod first, just strap the mod motor in (or boosted 10.5) and go and if there turns out to be enough people to support spec and mod, then do it.