Just to shoot one more comment into this discussion, for modeling gaming assets, I'm highly confident you can do that in Carrara with no problem.  If you want to see modeling possibilities, go and look at my gallery.  Everything in my gallery (99.9995% anyway) was modeled by me alone all 100% Carrara.

Every package takes some time to learn and Carrara is no different.  However, I think for the kinds of things you have mentioned, you will succeed with Carrara.

For my part, the kinds of things that I would like to see Carrara come forward with would be better clouds and atmospheric effects.  As for moving on to a different tool, Vue is a solution I have been considering.  To be clear, no package can do everything and even though Carrara can't do some things I want, I'm still generating a lot of great results with it on a regular basis.

One last note, a common thing I notice is that Carrara may not do things in the same conventional way that some other packages do but there is a very likely chance you can find a Carrara solution to do pretty much anything you want.  Just ask around here and we can very likely figure out a Carrara loophole to get you where you need to go.

-Kix