Seeing how mechanically reliable my 2 JG guns have been considering their extensive useage, I'm sold that they are by far the best guns to come out of China to date. I'm sure like any brand, they still have their lemons and problematic pieces, but they've been the one Chinese manufacturer who have learned their past lessons well and make very good looking, very durable guns for a really great price.
Yeah, I'll readily admit that other than the lower receiver, there's no stock JG left on this gun externally. But the mechbox is still stock and it's still going strong without even any prevantative maintenance. The only issue I have with the mechbox is what I believe to be a worn cutoff lever, so the gun only fires auto now. Not really a big deal IMO. No jams, misfires, feed issues, etc. I think that speaks very well in favour of JG.
Over the winter, I'll be popping it open to clean it and I'll probably toss in a spare lever from another cracked mechbox I have. But otherwise, I'm not touching anything else, and plan on shooting this thing as-is till something in the mechbox explodes. Then I can get a true test of exactly how durable JG internals are.