Originally Posted by pusangani
Personally I think WE and KJW M9s are absolute horseshit and the mags ALWAYS end up leaking due to the shitty side pin design
WE's hi-capas are ok, if you get one, keep it stock for as long as you can, it's when you start fidling that you run into fitment issues and things go sideways.
TM is my #1 for pistols, aftermarket parts makers tailor their specs to TM's specs so you know they're going to fit.
KWA is also pretty good and full metal and like FirestormX said, the parts are very easy to source, they're probably the best at parts support, WE is also good in this regard.
Good reminder/heads up.. I'm the type to take something apart before even shooting it, clean, debure, relube etc..