pretty noticeable difference in handling from 05 to the 02-04's...no need for different offset clamps or naything on the 05's, great handling woods bike!
Front forks are by far the best stock off-road forks I have ever ridden; the big drop in weight came w/ the 04 models, while the engine from 04 to 05 is very similar (w/ the 03 being the gnarliest running of the group, but least plush stock of the group)
To sum it up, the 05 has incredibly good suspension and handling (due to new frame and swingarm)...much better than the 03-04 models that I have ridden. It is one of those model years that all of the components work well together. If you can get a deal on a 05, I say snag it. Who knows if the 06's will work this well, and while the 03/04's are great bikes, the suspension and handling are just so noticeably better on the 05's