Wrong section. Belongs here.
http://www.m3post.com/forums/forumdisplay.php?f=124
If you're looking for power, no. You don't see much gains with slip on only, you need the full system. If you're looking for sound, not really, sounds almost exactly like stock, and even the full system sounds fairly close to stock.
Build quality is unmatched, it's light as a feather, it looks freaking gorgeous, and the power gains of the full system are just plain ol' fantastic. If these aren't your goals, I'd at least give some consideration to other options.
Just the conclusion I've
personally come to, as 2 of my friends have the full system, and 1 has the slip-on.