Taking a top from Niels Slot, I purged packages with "fglrx" in the name and now I find:
$ lsmod | grep radeon
radeon 357408 2
drm 203296 3 radeon
which is what I expect.
I also find much improvement. Page-down in firefox is faster - almost instant, but arrow-down is still slow.
Painting of the wallpaper is also nearly instant, and when I log in I can see five shades of wall-paper as it fades in from grey instead of two shades painting very slowly.
So - I think I now have the improvements that are to be expected at this stage.
Taking a top from Niels Slot, I purged packages with "fglrx" in the name and now I find:
$ lsmod | grep radeon
radeon 357408 2
drm 203296 3 radeon
which is what I expect.
I also find much improvement. Page-down in firefox is faster - almost instant, but arrow-down is still slow.
Painting of the wallpaper is also nearly instant, and when I log in I can see five shades of wall-paper as it fades in from grey instead of two shades painting very slowly.
So - I think I now have the improvements that are to be expected at this stage.
I'll report on crashes if i get any more.
Thanks to Andreas, Tormod, Niels and others...