I can't get the link to work but if you go to Yamaha's site, click products then choose the R6. Then on the left click specifications and from there you can compare the R6 to the 600R. Take a look at the specs. Heres the link to Yammy's home page www.yamaha-motor.com/
The R6 is a much more race oriented bike while the 600R is much more tame and better suited for daily street riding.
Single shock w/piggyback reservoir and adjustable preload, compression and rebound damping; 4.7" travel
Single shock w/piggyback reservoir and adj. preload, compression and rebound damping; 4.7
Hey, I had a YZF600R Thundercat when I lived in Japan, and I still think it's a great bike! It doesn't look as cool, or handle quite as well as the R6, but it's still a great all around bike. Light years ahead of the Can-O-tuna anyway.