Originally Posted by mjkeat
It forces you to use a support grip like how you would hold a beer can. Its not a natural grip (at least for most, lol) and doesn't do a lot for stability. I used to use a similar grip and after switching to a thumb over I've noticed a huge improvement in, well, everything.
That's why I stay away form VGs. It leaves all the rifle's weight above your hand, causing a lot of sway when you're swinging the rifle. Plus as mj said, it's not a natural position, and for me it gets uncomfortable after shooting for very long. If I were gonna use that type of grip, I'd just grab ahold of the mag well.
It's all personal preference. If VGs work for you, then use them, but I would recommend at least trying the thumb over for a range session, either with or without an AFG. If you try it, make sure and get your hand as far out on the hand guard as you can to get the most of the grip.
"Breathe when you can, shoot when you should."
"Qui desiderat pacem, bellum praeparat; nemo provocare ne offendere audet quem intelliget superiorem esse pugnaturem"