I just got a leftover '03 220 a while back. I had the same questions you did. Basically it comes down to your riding style - coming off of a ATK 260 I had to make some adjustments to my style of riding. No more screaming it up top, just ride a gear or two taller than you're used to and hang on-I'm actually faster on this bike than I was on the ATK, even though the ATK had more HP. The pull of the 220 down low is 4 stroke like, seriously. I ditched the airbox lid and added a FMF PCII silencer, and changed the jetting. It needs a FMF Gnarly Desert to open the top end up a little, and I'll quit there, I promise ;) Maybe I'll add the Boysen reeds to it as well to crispen up the bottom end throttle response a little.
Either way you go you won't be disappointed. Look for a leftover '03 - no difference in the bike vs. an '04, and you can probably still get a smokin' deal on one.
Thanks for the tips..... I work at a shop and we have a 220 "04" model that I can get a smokin deal on..... I have been told by friends that ride all 4 strokes that I will not be able to ride it much longer in Calif. and probable wont be able to get into the parks now..... I hope this is not true, if anybody knows, please let me know...