I run a TI Snow daily on my projects.. usually three of the four parts. You can get a lot of use out a Snow as long as you know how to optimize your patches. I rarely, as in almost never, run out of juice or get drop outs.
The Richard Divine soundsets are the heaviest consumption wise and they play back fine. You can get some pretty massive sounds with the virus without stacking 8 unison parts on it as well.
