Thanks for that Ratte
I tried it on my 1200 briefly last night. My monitor only goes down to 50hz so I had to try it through my IndivisionAGA. It did actually work but the Indivision got a bit confused and boosted it up to 57Hz, the screen was also not centered (quite a bit out), I assume this is because the Indivision needs the firmware upgrade to work properly.
Unfortunately I didn't have time to run any benchwork tests but it seemed faster than HighGFX 1024x768.