I've only been able to get 3 instances of GVI in V-stack with out crashing. I can get 4 sometimes 5 in Live and Forte, but Forte doesn't allow for drag and drop from the loaded sample window to a GVI track. Mind you, these are all empty GVI, no samples loaded and running the latest version.
Considering that I regularly ran Gigastudio3 with 6 or 7 banks fully loaded, this doesn't speak well for GVI. It's cutting my available sample load in half.
I should add that it's forcing me to stick with gigastudio for the time being. For those of you considering to upgrading, you should know you won't get the same amount as giga if you are using any of the forementioned apps as hosts.