i had a kjw cansoft m9ia, and a i have a kjw pt92, both are reliable. they can take tm m9 mags, but the tm mags don't have enough power to cycle the slide back far enough for the slide to lock after the last bb. they feed and fire fine though.
right now i have the m9ia slide sitting on the pt92 frame with a threaded barrel from 007, which is 14mm+ and also have the kjw supresor
only issue is the hop up requires you to take the slide off the gun and adjust it with a tiny alan key
and the tiny little hop up hole