AA's are very nice kits. I've had two. One gen 4 and still have the gen 3. Both functioned just fine. A little finiky at first with certain ammo, but once broken in ( couple thousand rounds or so of 40g Mini Mag) seem to function just fine with cheaper stuff. I've been very happy with mine. They pop up on the EE from time to time. Seen a few in the last year at fair prices. Just make sure it gets cleaned frequently. They seem to act up a little after about 300 rounds or so.
Still curious, does anyone here have any experience with the IGB Glock kits? They also look very nice, but have never seen one in person.