yes I have an AMD graphics card and I know that this side is expermental but I have heard on Blender Cookie that Cycles will become the standard Blander render engine so I am presuming that this side will get fixed. But I can say that it is quicker that Lux for rendering.
Also if you think this looks realistic wait until you see the next one that is still rendering.
I have always had ATI/AMD cards and never had any problems. Mind you in near on twenty years I have only had 3 PCs and I have never had as much trouble with softwae or hardware like others. Yes my last main PC died given the make and quailty of the hardware but for genral runnning day to day it has been PC stress free. Software issues I caused myself with my first compter taught me a big lesson not to mess with things you don't understand. Hardware side I clean out the PC evey couple of months. I don't DLed a lot of crap and install it. I am very selctive on what I install.
Anyways yep Nvida for me in the New Year. I don't like Lux even with Luxus anymore. Blender has shown me a new and better way, similair to the Octane Plug-in for DS and for that I will need Nvida, well two of them.