@SimonV
i had a 9800 pro on my pegasos2 and was great working in 2D under amigaos if we dont consider compositing/warp was not working there because not supported. overall performance was near a 4650Hd.
i was able to see it performance only on mos who was supporting not perfect at that time (probably now is full supported... i dont know).
in any way i think with 9700 you have to setup like i did for my 9800pro
you need to disable hardware accelerations preference for the gui.
but overlay will work in video play.
and all sdl software will run like never run before
here the video with mos
https://www.youtube.com/watch?v=m57aOBQvWao