That's right, Buble's secret sauce to being fast is that is skips the code generation step, not because of the number of dependencies.
Although there definitely is a performance cost to Babel's large dep tree as each of these modules have to be found by Node (which is inefficient). If you use Babel with npm2 it is super slow, because npm2's folder structure causes more lookups.
Yeah, I think that was a bit of a mistake by you guys. AVA's entire point is to be fast but it has the perception of being slow because you've made transpiling a core feature. I would drop that and let people do their own transpiling.
Aside from the concurrent testing, Babel with async functions built-ins is our second biggest "bullet point", so even if you were right it's too late. AVA is opinionated and I think the benefits (from what people have told us) gained from using the latest syntax with no Babel config are worth the Babel bottleneck—which isn't that bad.
