I’m in the same boat, and I recently made the jump to Cinema 4D from plugins like Zaxwerks ProAnimator to compliment my After Effects knowledge. I also tried to learn Maya awhile ago, and it just didn’t make sense to me. Cinema 4D’s interface seems to be more geared toward artists and visual thinkers. It also integrates well with After Effects and other compositing tools.
As far as which one to choose, I picked Broadcast because it seemed to have the bulk of the things I was looking for (including MoGraph, which is awesome) without being hugely expensive. It’s somewhat irritating that you can’t just pick and choose modules (I’d really like the Depth of Field Post Effect, but didn’t want to spend the extra $1600 to get Studio just for that). I figure I’ll get good enough at Broadcast now and then upgrade to Studio next rev.
If you do switch, make sure you go through a series of tutorials to learn it from the ground up. It seems pretty critical that you get into good habits with the program earlier. It’s a LOT more complicated than Photoshop, After Effects or any other program I’ve used.