My B-king had 2bros cf slipons on it when I bought it, but no tips.
It was way too loud for me.
I bought the gunmetal powertips for it(around $80), and they quieted it down a lot.(The tips with tubing on both sides of the flange, not just the outside).
2bros claims a 7 or 8 drop in decibels and I belive it. The tips took away the deep low rpm drone.
I could tell no difference in the power curve, no flat or weak spots, nothing noticeable.
The tips also came with 4 very thin O-rings, they were almost impossible to keep round to install, so I didn't use them.
I saw absoloutely no need for the O-rings either. The tips tightened down completely, not loose, not rattles, and no exhaust leaks around the tips what so ever.