I had a n 04 R6 and went to an 05 R1. at first I really missed the 6 and was sure that I could get it off the line faster than the 1.
That all changed once i got the R1 set up properly. -1 gearing, power commander, exup delete, and suspension tuning.
No. 1 difference is obviously power. this thing rips everywhere. those USD forks give a really solid feel as well. the handling is better but does feel slightly heavier.
There is a noticable differance in size between these two machines, even more so with the 08's. I'm 5'11" 190# and Mr.one fits me like a glove
In conclusion the R1 is and R6 with alot more balls.