Thanks for all the replies guys. Sounds like I need to go ahead and do it. Besides, the only irreversible part is drilling the slide. What do I have to lose - other than maybe a few MPG's? I have a 4-gal. IMS tank, so I'm not too concerned about that. I may also put the stock muffler back on there in place of the old Supertrapp. It is just too loud - even with just five discs in. I really thought that repacking it was the answer, so I did that last night. I was really encouraged when I opened it up and found only very small fragments of the previous packing. I mean, there was basically NOTHING left in there. A big, hollow can. I figured packing it would make a big difference. I had picked up some FMF 4-stroke packing at my local Cycle Gear store and cut it to fit. Stuffed it in, buttoned it all back up, fired up the engine, and... it was only marginally quieter. The packing may have taken the edge off the sound somewhat, but it's still too loud to suit me. If I lose a couple of HP on the top end with the stock pipe, so what. This bike is all about low-end and mid-range anyway. I ride on some dirt roads & trails that are frequented by horse riders - and nothing makes them hate you more than an obnoxiously loud pipe that annoys them (and everyone else) and spooks their horses. I'd rather be stealthy and try to get along with those people. When I was riding last week, I noticed a few of them coming towards me ahead in the distance, and before I got close to them, I just pulled over and shut the beast down. As they came by one guy said "I owe you a beer". See... a little bit of courtesy goes a long way sometimes.