Radeon 7500 is pretty fast card.. it was made as highend card.
On my Pegasos1 I get 75MB/s write and 23MB/s read with 7500. With 9000pro and 9100 (rebadged 8500LE) I get 75MB/s write and 15MB/s read.
I also tried to make some benchmarks with couple of programs and 7500 seemed to be sligthly faster on almost everything, not slower at least. Tests were made with GLQuake, QuakeIII, CgxBenchmark and p96speed.
Also the compatibility seems to be best with 7500... like Mawi's demos work with it, but not on 9000-series cards. Some other 3D programs have some little non-serious issues with 9000-serie, but not on 7500...
