Happy with Carrara or WM? WM is a work of genius as far as I'm concerned. Carrara? It's OK - although I haven't seen 8 yet. To be frank, I've never managed to push Carrara into doing anything I couldn't do with the usual modeller/terrain generator/scene editor/renderer pipeline, but it is handy, I suppose, to have most of those things in the one place. It certainly cures a lot of import/export woes. To be even more frank, the only reason I ever considered it was that I could never get my head around Blender (but, once again, I haven't tried the latest version in which the interface has been redesigned).
In a perfect world (coming soon, folks
) I'd have an understandable Blender, a completed Makehuman, the open-source version of Zbrush (fat chance!) and WM - oh, and the GIMP, although it doesn't quite reach Photoshop standards yet. You may detect a preference for FREE there! In a slightly less than perfect world, Poser or Daz will finally get their dynamic cloth to work.
In the meantime, I have to use things that allow me to do what I want in a way I can understand. WM hits that nail right on the head and Carrara does too to be fair.