In my opinion, if you are a mature and responsible rider, that bike is perfect. Its not too expensive, and not too new. Its priced fairly. And if you've riden dirt bikes before, you have some experience. I think if you just take it slow to begin with, you should be fine.

I started with a 97 Katana 600 (about 430 lbs and about 80 hp) and I got bored very quick.

It also depends on your size though.

Im 5'10", 155 lbs.
If you are not too much smaller, a 600cc CBR wont be too much power for you.

...just my opinion though...