X-ball silver is what ive always used, shot some diablo heat but only when my field was out of X-ball.
Strengths:
Very Quiet. Accurate for the price.
Weaknesses:
It is a stock barrel after all.
Review:
I can honestly say that i have never chopped a ball in my matrix. I dont know if its from the Anti-chop eyes or the barrel, but ive never chopped a ball, and I play almost every weekend. Very quiet, if you move bunkers it takes a second for the opposition to find you, but by then you should have a bead on their goggles anyways right?
Conclusion:
If your looking for a cheap, quiet barrel that shoots well, get this, if you've got the dough, get a pipe kit or a freak set, or a Ti boomstick if your loaded with cash :P