if you have deep enough pockets to keep it together its a beast, but they have a slow crank time so thats gonna kill you on the start. I have 2 racing buddies that OWNED them and they spent a fortune keeping them running. I still to this day dont think there is a 450 stock that can out run one though. but top speed isnt everything in the gncc. they handle great, aluminum frame that makes it light but damn they are high maintence.
1999 416ex
practice bike
2005 trx450r (kicker)
in major rebuild at the moment.