Well, I dont have really big impressions but we ran them head to head in a straight line a few times.
2003 GSXR 1000 - 2900 Miles, Full Yoshimura Exhaust, -1 Tooth front sprocket.
2004 R1 - 200 Miles, Stock.
Weight difference is about 40-45 lbs with the advantage goign to the R1 rider.
Did a few runs starting in first around 4-5k, I would pull the R1 right away, but after the R1 gets into its huge RPM range up top it just starts to pull on me, never pulls too hard but is starting to pass me by 3rd or 4th gear. The R1 would do this every time.
We switched bikes and of course my GSXR 1000 would just stomp the R1 due to the weight being switched around. So I think riders of equal weight and the GSXR 1000 would prevail, but I do have the full systgem and -1 tooth in the front.
The R1 is fast, it feels slow down low but once you get around 8k it just opens up and keeps pulling hard all the way to 13+k...
Its a very kick ass bike.