No problems passing 6GB here in Vue 7.2.  Simply try importing a Mudbox .obj sculpt and adding some Vue displacement...  Or any high poly object, for that matter.

Vue doesn't handle imported geo very well at all.  But I suppose most of their customers don't use high-poly geometry, either.  It'd be nice, though!  I have some rather decent scenes waiting for Vue 8 or 9 to catch up before I can actually work on them or render them...