I have a bad habit of grabbing the front of the magwell with my non-firing hand, which is obviously terrible for stability. To remedy this, i put a verticle foregrip on my rifle, to give my hand a more natural place to grip, while extending out my arm further forward for added stability. As others have said, if you just grab the verticle grip, it just makes stability worse than it was before. Thats why when you use one, about 90% of your hand is firmly holding the handguard, while the pinky and ring finger push the grip back into your shoulder. Same theory used in the concept of the afg.
You want to be a martyr, I want to make you one.
The AFG's are a cool idea but it's totally up to you if you like them. Almost everyone I know who have tried them took them off pretty quick. They take up a lot of space and, to them and myself, didn't feel as good as the regular hand guard. The two exceptions were owners of an AR and AK pistols. Since the vertical foregrips aren't allowed it was a good and legal (according to the California DOJ at the time) alternative. So just try one and sell it if you don't like it. Easy.
Mom's comin' 'round to put it back the way it ought to be.
Anyone that thinks war is good is ignorant. Anyone that thinks war isn't needed is stupid.