I just picked up an 03 YZ450F. I'm also just getting back into dirt riding. The bike is in need of a new exhaust and I'm looking at the Dr.D slip on. The head pipe on the bike seems to be in good condition it's the mid pipe and slip on thats trashed. Is there any advantage to buying the Dr.D complete system with their head pipe. Or is the stock pretty much the same? I know on road bikes the stock headers are junk but these are just one pipe with a bend. Should I find a slip on or get a complete system? Also is Dr.D a good exhaust? I don't need best most expensive top of the line but I do want something thats of good quality and will last.