I own a G&G CQB-R. http://b2b.guay2.com/eng_our_product/g4cqb_r.htm
I brought mine as a trail to see what the design quality and workmanship was like compared to the other main brands of Airsoft Weapons. Also we had a special deal for Airsoft New Zealand members.
I would personally say its a reasonably good weapon for its price and it has a metal body.
Problems we encountered with the G&G weapons............
Some of us had issues with the Mag Release - They brake easily, So you should replace it or order a spare one.
We also had issues with the King Arms Mags not fitting into the Mag Well properly. (Only on a couple of the G&G GR16's)They became loose and wobbled around in the mag well, and sometimes just fell out while in the field.
What ever you do..... DO NOT twist the rear stock at all on the CQB - R , Because the battery wires poke through a tiny hole in the stock, and you will cut them off. (as I did)
We also found that the gear box screws had been over tightened and almost impossible to unscrew without damaging the screws / hex keys.
Reliability is still to be assessed as they are still too new to comment on. Other than that they seem to be good reasonably low cost weapons for the beginner or someone with a defined budget.
I am personally a Tokyo Marui fan, As they make very good quality and reliable weapons which have been popular with most of the Airsoft Community world wide. But they can be a bit pricey.
You can upgrade them easily with G&P or King Arms accessories such as metal bodies and front ends etc to create your own personal touch.
TM-CAR15, TM-G&P M4/SR16 Custom, TM-M4A1 Custom, TM-G&P MI6 VN Custom, TM-SR16, TM-M4S System, G&G G4-CQB-R.
2x TM-VSR G Spec's
Marushin Mossberg M500SSB 8mm.
TM-Sig 226, TM-Socom Mk23, TM-Tactical Master. TM Glock 17 3rd Gen.
You Can Never Own Too Many Weapons !