Cheap airsoft ones are very flimsy. I used to run what I think where better made but still airsoft ones. I found them useful on milsim weekend games or resting your gun when in a building or defensive position. Saves you from putting it down in mud and also keeps it in a semi guns up position, especially if you in prone position lying in ambush. However they are huge as a vert grip, i prefer the Magpul MVG.