None, I've only had two guns and my first was really cheap conpared to this gun.
200 count viewloader hopper, 9oz co2
Expansion chamber, electric hopper, 14-20oz co2
Very accurate, dovetail sights, good on co2 and the hopper doesn't obstruct your view.
Difficult to clean, difficult to cock, chops some paint.
I got this gun used so it may not perform to the best of its ability.I found that this was a really solid gun. It's very consistent and is very accurate. Although I would get a an electric hopper casue it has a tendancy to shot two or three paintballs the first time you shoot it. Also, you can over shoot it and chop alot of paint with a gravity fed hopper. Also, you can get alot more use out of your co2 if you get the expansion chamber for it.
I really liked this gun and it is perfect for begginers but I wouldn't try to use it when playing speedball or playing in an tournament because it just doesn't shoot fast enough.