I'll say this twice: The ball must be able to roll down the barrel which goes completely against conventional paintball. If the ball catches instead of rolling, it will stop or slow the backspin.
With the right paint and the right barrel, this product actually works. I have achieved 100%% of shots fired with consistent backspin using the Lapco Z-Barrel (really a Lapco Bigshot .697 bore barrel) as mentioned further down at www.g3pb.com I started out using a .693 CP barrel, but that wasn't big enough. With that barrel only about 60%% of shots fired received backspin. Get a really large bore barrel or this will not work. Accuracy is good, and the range you get is incredible. Since you only need one large bore barrel, there's no need to have a lot of barrels.
You can also tilt the gun sideways and get the balls to arc left or right to hook them around bunkers and trees. Since the backspin is adjustable you can turn it higher or lower or even completely off to get more range or drop a ball over the top of a bunker.
Also, the body makes your mag look quite different. The manufacturing of the powerfeed is very precise, all dovetailed perfectly. Allows you to use cocker barrels on your mag.
Weaknesses:
It's a bit expensive and hard to find. Needs the big bore barrel, and since most people don't try it with anything over a .693 bore, they think this body doesn't work very well. The ball must be able to roll down the barrel which goes completely against conventional paintball. If the ball catches instead of rolling, it will stop or slow the backspin.
Parts are also hard to find. You have to find the right paint or you'll break a lot of balls in the barrel. I found that Nelson Anarchy tends to break some while PMI Premium seems to work quite well. I'm sure using something like Marbz would work very well, but they cost a lot. You get what you pay for.
Conclusion:
Great product once you get the right barrel and find a good paint to go with it. Ticks off opponents that can't reach you with their more limited range. It's nice to aim straight at a target that's 40 feet away instead of having to aim over it.