AFAIK Vue actually needs more RAM then Poser to run comfortably. It's just less prone to crashing if it doesn't get enough. And like pjz99 said, it does have a few cool features over P7, though they can take a very long time to render.

P7 is better at RAM management then P6, but it's still buggy when it nears its 32 bit limits. For me it starts becoming unstable at 2.0-2.5GB+ even though i have a 64 bit OS and 4GB RAM.