I have a kirenex.
The selector switch is a bit loose but that's about it right now. I've shot about 500 - 700 bbs in my basement and no problems as of yet. I just need to get myself a better battery and charger but that can wait till later or until I start going to games.
For TM compatability; I bought a metal receiver of huang and he states that his receivers are TM compatatible. I tried to put the Aftermath kirenex mechbox in the receiver and it doesnt fit. The mechbox is too big. That's all I got. Hope it helps.