I've used laptops and desktops with GPUs from all 3 manufacturers. The only issues I've had were either really minor (ie. About the same as the other platforms)

I've used laptops and desktops with GPUs from all 3 manufacturers. The only issues I've had were either really minor (ie. About the same as the other platforms), or with graphics switching (ie. Bumblebee). If you're just using the recommended drivers for the hardware I'd be extremely surprised if it was as unstable as you describe. For reference, it's recommended you use the open source drivers for Intel and AMD, and the proprietary drivers for NVIDIA. No PPAs required.