I've had this for a year now and it still performs great. It is my first gas gun. The blowback is very crisp and the gun is very accurate and shoots at a reasonable velocity (as advertised).
I've taken good care of it by using good BB's and cleaning/lubing it after every use.
Unfortunately, it jammed a lot when I first got it, and it still does so now every now and then.
It has a few quirks as well (see cons).
Once the cosmetic ejector flew off and I had to buy a new one for $7 from KWA. I superglued the new ejector on and it's still stuck there.
Overall it's a good gun though it probably was not worth the $165 due to the weird habits.
Works with propane gas
Realistic appearance (with a unique serial number) and action--slide locks back with last shot
Jams occur every now and then
Safety sometimes doesn't work (press hard enough on the trigger with the safety on and it will go off)
Magazine is very vulnerable to dust
Magazine has to be loaded a certain way or it will jam
BBs get stuck in magazine if loaded the wrong way and the spring + follower in magazine is let go.
Not super-reliable, but when it works, it works very well
Rating: [3 of 5 Stars!]