Tested Camerupt a bunch of times, and while it has some potential when in safely, that typing is just too exploitable to be a serious threat in OU... It can certainly nuke plenty of things on the switch with Fire Blast/Earth Power, but it's a lot harder in practice with things like Greninja, Azumarill, Lando-I, etc waiting to maul it with their STABs. I've been running 252 HP/252+ SpA/4 SpD, for what it's worth.
Altaria on the other hand, has just been downright impressive. I'm running a bulky DD 252 HP/4 Atk/252+ Def Impish set, and it can reliably set up 1 or 2 DDs, checks pretty much every dragon in the game (even potentially beating the beast itself, Mega Mence 1 on 1 if it's taking recoil from Double Edge, or if it comes in BEFORE Salamence begins DDing without Double Edge), is a solid check to Zard Y and Tyranitar particularly if it comes in with Cloud Nine after they set their weather, and is basically a threat to pretty much any physical attacker that isn't carrying powerful steel or poison stab (not much, in the latter case). The only mild drawback, really, is that you have to be careful getting it in before it Megas, which goes for most Megas obviously.
For my defensive set, I'd like to try Body Slam over Return for the paralysis chance, but I think it fails to OHKO Megamence back after Double Edge recoil, so I've erred on the safe side and went for the latter for now. I'll have to try facade, as I've noticed Altaria is a magnet for status, it gets Toxic'd or Wisped in well over half the matches I play with it.