As I only bought the part to serve as a fingerguard, it is fantastic for that purpose. I mostly play woodsball, so for me it is a big help. Then I decided to go to a SmartParts Progressive barrel, and moved the suppressor to the tip of the barrel. Bad decision. At first I thought I got a defective barrel. No velocity adjustments helped. No grouping, no accuracy, and the faster you would shoot, the more scattered your pattern would be. I removed the barrel, and went back to the original Tippmann barrel. Improvement. Swapped it for the Big Shot - still good. Then I thought about it and put the Progressive back on without the suppressor. Every shot landed as predicted. Great pattern, seemed really happy around 275fps. Put the suppressor back towards the gun -- still good.
Conclusion:
If you get this piece, it is a very nice-looking accessory. But, as you may have assumed already, it will not quiet anything down, aside from your buddies. People will ask you how quiet is your gun, or if it's legal, or if they can try your gun with it on. DON'T PUT IT OVER THE FLUTING OF YOUR BARREL - YOU WILL REGRET DOING SO, but by the time you realize it it will be too late. You will have scuffed the barrel.
I will give it a 9, since I feel that Lapco should have warned buyers about this issue.