I have the Sub2K with the Glock mag option, it is a really fun gun, very accurate, very reliable. The 30-rd Glock 18 mags make it balance well, but the ten or 17 rd mags work fine too.
The Scherer mags are total junque and I would never advise anyone to buy them for any pistol. Factory Glock mags are cheap enough to just buy them!
I shoot Rainier 124-gr HP's loaded to +p in it, it is what has so far worked best.
I have the BlueForceGear charge handle, Hogue grip sleeve, 1" butt extension, and the KT Folding scope mount with a Browning scope.
It's a hoot to shoot and the fact that you can have a real live rifle with 30-rd mags in your gym bag is like a magic trick.
Best $300 I ever spent.