Sold my 99 ST4 last fall prior to moving from NC to AZ. Yesterday, I picked up a 2002 ST4S. I was debating between another 99 ST4 with lower miles, but the allure of the S model upgrades won out. Wow. It felt so familiar and yet so different. It has a few modest mods - kevlar brake lines, Corbin seat, DP rear sprocket. I didn't take the time to count the teeth, but I noticed that it jumped from zero to 100 in nothing flat. I was a bit surprised at the different feel of the engine. Seat of the pants analysis was very favorable.