here is my 2 i had an 2002 f4i good bike but i out grew it pretty fast.if you are forced to buy another bike u should upgrade.a 600 rr is a good chioce but again u will out grow just real fast.i bought a 2005 rc51 if you like horsepower and a bike that you will see all the time. go with a 1000 rr.now if you want a bike with lots of low end power looks good not alot of them around and loud as hell with pipes go with the rc51.this bike handles its ass off. solid bike.but then again i own one.also you could just buy a 600 and wait to 2008 and get the new 1000 rr.