If you can find a good one, the first generation GSX-R750s are good bikes, with no real major issues. The power on the 750 was OK, but weighted toward the top. The trouble is, most were flogged and abused and thrown down the road a long time ago. Good ones are out there, but getting hard to find. I preferred the 1100, so I bought one. It had better power, a beefier frame, and better suspension.
The next generations added power and weight. They had to change because the original frames weren't up to racing power levels. The 1100s really got porky. The 750s remained peaky and the oil cooled motor went thru stages where Suzook shortened the stroke, then thought better of it and went back. But any of the air/oil cooled engines are strong and reliable. I always considered the build quality of the GSX-Rs up there with anything Honda was doing. I put almost 20,000 miles on my 1100 with no problems before I sold it.