As many before said, this gun is very accurate. During practice shots others with their guns can't do as well as I can do with mine. That's of course subjective, but when we switch guns I can't do with theirs what they can do with mine.
It is very light which makes aiming much easier (you don't get tired carrying the gun). It has great look and feel. The feeding mechamism doesn't obstruct your view, which again, makes aiming much easier.
Select fire is just awesome, you can switch with your thumb pretty much while aiming and shooting (sometimes it is good to switch fire mode during the game - saves paint). Single mode itself is good enough to keep up with high end guns on commercial fields.
Not the quickest maybe but very good and helpful customer service. These guys are engineers, not salesmen, so they won't get back to you immediately (sometimes actually they do) but when it happens your helper will be very competent. Great manual and video showing how to take care of the gun.
Even if the gun with part and maintenance isn't cheap, it also places below really high end guns, delivering really comparable or outstanding performance.
Unisizer (the soft plastic ball detent) does a great job matching to any size painballs. It is kind of like a self-adjusting "freak" barrel.
Stock barrel is top notch. In general you don't need to spend extra $$ on after market parts as everything the gun comes with works great.
Relatively expensive to maintain. Magazine mechaism is very delicate. Doesn't get damaged by itself, but at the beginning you'll be error prone and eventually bend pins. Once this happens you're out of the game for the day (unless you have a spare). Forget about field fixing it unless you've got proper tools and a table with a clean cloth ;)
Velocity adjustment is a pain in the butt. After you chrono, you have to take the magazine out, shoot the remaining paintball, and then insert your adjusment tool into the barrel. The good news is that most of the time you'll be doing it only once at the beginning of the game.
There is a danger that this gun will become your hobby. ;)
I bought this gun a month and a half ago as a third gun (after Tippmann ProLite and Tippmann 98 custom with addons) and have been playing every week since. I was looking for something very accurate. I wouldn't call my style of playing a sniping, but it does involve not shooting a lot of paint with a lot of manuvering, flanking, etc. Turns out that I got a perfect gun to match my style. Even with the auto enabled I use twice as less paint as my friends with higher end semis. I often get twice as many kills too.
This gun requires to be taken care of. If you expect accuracy and consistency you have to keep it clean and properly lubricated. None of this "run hot water through it and forget about it stuff". So prepare to have time for it. Since it is - like somebody here said, as a swiss watch - you'll have fun if you like playing with mechanical stuff. Otherwise you may consider getting a different gun.
The bottom line is, if you are prepared for maintenance, this gun will "pay you back" and you will not be dissappointed.