I am liking this MPA 10sst. It holds 30 rds and goes for 425.00. The thing is I don't see any reviews for it on line and I don't like they are not showing you the 6 inch barrel that screws on.
Have you held one? That was the most of my experience, it did not balance well and the grip is pretty rudimentary and uncomfortable, I think you'd be better served with a regular pistol since 30 rd mags se available for such a wide vareity of handguns these days.
I stood next to a guy with one at an indoor range, he had a red-dot, flashlight, laser and at least one other doodad clamped to the rails (he had a rail on the bottom of the upper as well). He has was having trouble holding it and couldn't get comfortable. At bedroom distances he wasn't shooting as well as he was with his H&K pistol.