Opensource radeon driver is pretty good if you don't need 3D. I would actually say that it is much better then the AMD one - there are no problems with suspend and the card initializes more quickly.

I take it you will need 3D if you are in the market for Steam.

I also went through all sorts of hell with proprietary AMD/ATI drivers, and I needed them for OpenCL. To this day my Desktop is a pain to use but OpenCL works fine. Sadly they make the best cards for this purpose by far, otherwise I would get something else.

Yes, except for power usage. The blob is much, much better at keeping my laptop's battery alive.

Or an Nvidia, or an Intel, or ... All accelerated cards have had their share of bugs.

Intel run pretty flawlessly. They're just comparatively underpowered for gaming.

That has not been my experience, but admittedly it has been many years since I bought anything with Intel graphics.