Chesnaught is one of my bros, but I kinda feel conflicted about its competitive usage. Greninja is arguably the best starter of this gen, and my 252 ATK / 252 DEF Chesnaught seems to get killed by the non-EV'd trained flying type moves of a Salamence. That prolly doesn't bring good news, I'm afraid.
I'll try to use Chesnaught competitive-wise nonetheless, but I'm afraid I'll have to do it another year with a "cookie-cutter team" (It'd be cool if my fav mon team was actually pretty good).