I've only had my hd since November and love it. It is my first Harley and first bagger. It's a 2010 Ultra. I should have got one ten years ago. The previous owner added a ton of chrome and cosmetic items, but the drive train was bone stock. My first modification was to cut the cat from the header and installed a FuelPak. I rode the bike this way for a few weeks and didn't notice any performance improvement. Then I installed the high flow air cleaner from fuel moto. All I can say is wow! It feels and sounds like a different machine. I bought the fuel pak on eBay for $100 and the AC was $145. The cat was only $7 for new gaskets and I did the work myself. Is there another performance upgrade that might provide the same return on investment in the areas of improved power, handling, safety, or reliability? Right now I'm thinking this might be the best $257 I will ever spend on this thing.