I haven't done THSCC track events, so take this as the opinion of someone who has driven VIR South and VIR Full and most of that was in a Spec Miata for SCCA Club Racing weekends.
I would much prefer VIR North for sprint races and even ECR length enduros. The big deal to me with the sprint races is that you waste a good deal of the race just going straight. That means fewer opportunities per race for passing. I was amazed the first time I went to Road Atlanta how much faster it seemed like the sprint race was over...there was just more action for the entire time.
That said, I like VIR Full better for the big enduro. I guess the reason is that you spend more time in those straights.

Gives you much needed "rest." Sure, that's being a wuss, but well, I yam what I yam. Can't wait till November, that's for sure.
I can see where small bore folks would prefer VIR North for track days whereas big bore folks might prefer VIR Full. If I were in a big bore car using Full for sprint races probably wouldn't bug me as much (if at all).
--Donnie