Might be the first to nay say on this weapon.
The gun itself is good. Lots of metal, but not enough metal where there needs to be. Primarily the upper receiver.
Being a TM clone, an old one at that, it still uses the dreaded 'Tabs' to secure the two halves together. I used to own a TM m16a2 that broke both tabs. I've tried many times to fix the receiver, but I just ended up ditching the plastic and buying a metal body, and continued to have problems (Dboys, lol.)
Anyway, A freind of mine baught a JG S-system and ran into quite a few problems.
1) The upper receiver comes in two halves. in which the upper part of the rail system screws into. Being cheap plastic, the weight of the front rail (Which is pretty heavy) will either break, or strip the screws and plastic. and cause the front of the gun to wobble and droop a bit.
2) Tabs broke. there is currently 1 tab keeping his gun together. The RIS on the front is just too heavy.
3) Back to 1), since of the strange receiver/fake rail design. Replacing the body will lead up to having to replace the rail of the S-system since it cannot attach to a new body which actually has a real receiver rail. Lol, Apparently there is a part out there you can buy so you can actually use the thing but from my attempts its pretty hard to come by.
All in all, I'm sure the gun would be great, just be careful of the issues this gun tends to have.