The fact that scopes are rarely useful in an actual game are the primary reason I don’t recommend them. The entire idea behind a scope is that you have a chance to look through it, focus on your target, take a deep breath and pull the trigger. This works well with target practice and sometimes in hunting, but in paintball you rarely have time to do this. In most instances, as soon as you see movement, you have to be able to fire almost instantaneously. This means that you simply don’t have time to use the scope.
One of the reason that I don’t like scopes, is that paintball guns simply aren’t very accurate where you need a scope. For example, if you are shooting at a target that is 200 yards away with a rifle, a scope will help you aim. With a paintball gun, the effective range is closer to 80 feet, and you really don’t need magnification to shoot that far. What happens, is that people think that they are sighted directly onto their target, and then the fire the gun, but the paintball will not go that far and they miss horribly. A properly cited paintball scope is probably sighted at about 30 feet, and most people can see well enough that they don’t need the scope. With little bit of practice, you can sight along your barrel and shoot just as well.