I have both (well, Studio 2.1, not 3) but find it very hard to tear myself away from Bryce, because I love it so much, and also I mostly use it for terrain, the area it shines in :) I'm not that experienced, particularly in animation, so tend to use Bryce for animation because it's so easy, and you can load preset paths, or save your own paths to the library. Don't everyone shout at once and tell me that you can do the same with Studio 2 - you probably can, I just haven't been motivated to find out how to do it. For animating objects/humans or morphing I use Poser4, again 'cos it's so easy. And Bryce has easy-peasy multi-rep - just wish you could export native Bryce objects as .obj, then it would be truly fantastic.