They seem to be bombproof from videos I've seen. The gearboxes are meant to be full steel gears aswell
Airsoft Forums UK
Zak Da Mack
two_zero
some swear by them some say they are rubbish. externals seem to be fairly strong. Personally I am to sceptical to consider buying them when there's VFC and RS. also it seems they have straight out lied about their designs (ea. who they clone), which is not cool. would be neat thou if someone with too much money did a side by side test of a few AKs.
Esoterick
Thing is some people say the same thing about VFCs. From what i've read they are as good as LCTs which are highly regarded
