totally worth it too. i went from pedaling around the block to get started to pushing it to get started. i love it. BTW, for a 15.15 SHA, 58ish jet is pretty much the accepted standard for the moby dellorto conversion, w/ the stock llorto airbox. Some go a little lower, 56 is the lowest ive been and ive heard as low as 54 (seems a bit low to me). I never finished tuning just right with a "performance" air filter cause it was getting to be winter, but i'd say around a 62 would be right on the money.