I had an 05 Raven and wasn't all that impressed. The power delivery wasn't as linear as the gixxer or hondas I've had and it felt quite top heavy. Solid brakes (radial brembos), especially after SS lines.
I would think the 600RR is much better bike, they moved the tank lower (the actual tank part you lay on is just a fairing) and the bike is a lot smaller.
Aside from a tubo busa, on a budget I'd get a 03-04 600RR and spring for inverted shocks, ohlins in the back and radial brembos. I don't think they changed anything else on it over the years.
06+ r6's got even peakier. I didnt think it felt havy, at all. it did seem a bit top heavy, but that was due to the utter lack of rake in the steering.
of course, I came off of a 440lb bike to it
riding my neighbors 08 gsxr600, it was way more comfortable ergo wise.
I don't think there's a whole lot of difference between the big 4 (Suzuki, Honda, Yamaha, Kawasaki) in terms of 600cc super sports. Pick the one that you like the best and that you feel most comfortable on.
If you want something different I'd try the Daytona 675.
they are all actually noticably different in feel in my experiences. at the top end, performance onm a track, sure, all within a small range. but feel, I think they are all different
the daytona is way different, power delivery is GREAT for a bike of its size.