very good review there, m8!
i have a g&p m4 cqbr, and i can totally agree with everything he said(except for the stock, mine came with a battery stock)
rate of fire is very high with a 10.8V battery(maybe not quite as insane as the vfc's but still extremely good)
as for mags,
i have used mag and g&p midcaps, ka lowcaps and ca and ka highcaps. they all fit and fed. the mag midcaps gave out on me when loaded with about 80 shots, but that was a magazine, not a gun problem. i used to have a ca m15a4 before that, and i was greatly dissapointed with the magazine compatibility of the ca.
in fact, the g&p is so good i even have a bad conscience about getting an hk 416
