[Hectic]

Lol, likely not the greatest for airsoft but in some situations it may be practical in saving fractions of a second, not 100% sure but most comps seem to require mag retention, and in the field mag retention is kind of important, perhaps if you are in a fixed location it may be semi use full but again only fractions of a second faster for those who practice.
edit: I could also see these being an issue when you are prone, they would pop out a bit and hit the ground and you'll have to manually remove the mag anyhow.