I've had a few JG M4/M16 and I think they are pretty solid AEGs. Well worth its price, and I'm not sure, how much lower quality they really are from a TM M4, aside from ACM high lemon rate.
The links below are a couple review from ASC members of the JG M16, which is pretty much the same as the M4, but longer and maybe more accurate due to the longer barrel.
"Certainly there is no hunting like the hunting of man, and those who have hunted armed men long enough and like it, never really care for anything else thereafter."
- Ernest Hemingway