After I learned how to actually use my VFG, it turned out that I was able to move the firearm much faster between targets.
The key, I found, is not to hold the VFG with a death grip, but rather to use it to pull the rifle back into the shoulder, using the bicep for pressure...
Exactly. I don't own an AR15 yet, but have been shooting the Army's for about a decade now. I found recently that switching my front hand from barrel support to pulling back on the magazine well (not the magazine) is much more stable. When I do buy my AR, I will definitely invest in a forward grip.
I use a folding VG and find it works good, took some time to get acquainted to but over all is good. I put my flashlights PSI switch on the grip and it works great. I found when I have to stand around for a long time it helps hold the rifle up rather then letting it hang on my tac sling around my neck.