After some thoughts on upgrading to Vue6 I...I'm holding off.  I just created a "god lights" scene in Carrara5.1 (fully interactive/animatable vol. clouds with a vol. cloud lab), and it looks quite nice!  I also have SSS, translucency, animated plants, super accurate surface distribution, displacement mapping, a decent particle system, and 16bit RAW terrain import (great with GeoControl -- absolutely matches Terragen2 for terrain modeling only).

Vue6 Infinite will have to prove "itself" to me this time around, as it actually adds little to my tool box -- from what I've seen.