The new driver has cleared up all the 2D issues I had, the machine is actually usable now. So thanks to Aaron for that.
OpenGL benchmarks are still terrible, 30% below the figures from a 5 year old, embedded 6200 TC. This is disappointing since I never expected an IGP to have stunning performance compared to a discrete GPU, but I'd expected it would at least match performance and maybe achieve a 10% edge over the older kit.
However I've heard that this might not be a driver issue, that the 8200 just lacks the power.