All that generation GSXRs are great. I love the 750s too - they're definitely less intimidating if you're getting after it which is fun on track. Less versatile on the road perhaps as you miss the astonishing smooth-turbine midrange shunt of the thou.
Gearboxes on big Kawasakis do tend to be a bit "agricultural".
IMO the 750 is the K5/6 GSXR to have ... much more fun and really rewarding to ride.