Cat was buggy in 2011, and nvidia physx plugins aren't out for 2013. So this makes 2012 the obvious choice. But then, cue dramatic music, the skin modifier is utterly broken in 2012. How did it release with a core feature destroyed?? Oh well. No problem right? Just install the service packs. Oh wait, the service packs break your CAT rigs. I really don't want to get multiple versions and keep switching between them. If Autodesk had a face I would punch it. Does anyone else share my pain?