I just did the hi comp piston and base gasket on my 2001 for the same reason. Finished kinda late but in the short ( it was cold, I was in a tee shirt from working inside with heat) ride the difference was noticeable. I weigh 300lbs and and for me the bike wasn't as "crisp" as I would like. Well know it is! It's been killing me not being able to take it out due to work and rain, but tomorrow morning
My bike has stock exhaust, and heavier springs thru Jesse at Keintech. He provided the Hi comp kit I used.
As to difficulty, I had help, but the manual makes it easy, and setting timing was a breeze. Also you dont have to remove engine from the bike.