Excellent review. I also own a KJW M9 FMV, one of the first, and I must say although I love it (its the first airsoft gun bought), it has had a few more problems that I know other people have experienced-
First, after about 3 weeks my trigger spring broke. Hard to replace part. This was apparently a fairly common problem, although I have not heard of anyone whos purchased a new version and had this, so I think they use better spring metal now.
Also, for the first two weeks or so of use, the slide would get locked back with the gas cylinder stuck fowards. This only happened probably