I have done a LOT of larger images with 20-60hr renders by the Resume Render method - just let it go all night, stop in the morning so you can use your computer for work/personal use, just before going to bed load up your scene again and hit Resume Render (loved it on Bryce, too - yes, fellow former Bryster here).

I'm loving V6I as well! Noticeably faster renders (though can still bog down with complex scenes and/or materials - that's to be expected with ANY 3D program).

And yes, I bumped my systems up from 2GB each to 4GB each and everything goes faster - even Vue - so I'd suggest getting as much RAM as your computer would allow.
Hope that helps-
-Lew ;-)