Hmmm I never have any slow down at all when moving around my scene everything is as smooth as hell no jolts no nothing. Then I render...... if for example I had a render that is going to take 5 hours and I had an extra 6 gig of ram is it going to be done any quicker? Even if it was an hour quicker it would be worth it, however if we are talking marginal differences there is no point. I found a benchmark list on the internet where they tested 6 gig vs 12 gig of ram on a multitude of apps and games, there was a difference of about .5 % performance increase from having the extra so it recommended not to even bother. I have never seen Vue use all 6 gig of what i currently have either... apart from once when attempting to render a 42,000,000 polygon pic then it said out of memory I would not attempt a render like this anyway unless it took less than 24 hours (which i doubt!)