jeez you guys sure are close-minded.
reasons this is better than a pistol (just for the sake of being devils advocate)
1) longer barrel (higher velocity for gas guns)
2) stock and front grip increase stability and comfort over handguns. (undeniable common sense)
3) holds a 30 rounder while folded (ever tried running around with one of those in your holstered glock?)
4) rail for optics (never seen a glock with sight in a holster that wasnt for IPSC)
i rest my case.
i should also note that you guys are comparing this thing to pistols. why? because it has glock internals? i would compare it more to other SMGs like an MP5 cause thats really what it was designed for in which case it is pretty cool in that it has all the capabilities of that gun with the aded benefit of folding.