Look through this thread:
http://www.airsoftcanada.com/showthread.php?t=36977
There are a lot of people that have the KJ M9 (myself included). You can learn a lot about it from peoples' personal experience over time, rather than getting a review of the brand new, out-of-the-box gun.
Personally, mine is my favorite, most powerful pistol with the best range. My TM P226 beats it out in accuracy, but only very slightly...