I've got an AMD laptop with AMD graphics and have to install the Catalyst software to get responsiveness from Ubuntu graphics. If I don't completely uninstall and purge Catalyst before allowing system updates, then reboot using a custom boot command, then shut down and reboot (with the custom command again), and then reinstall Catalyst, I end up with a machine that boots to a black screen and is essentially useless until I wipe the drive and reinstall from scratch. With 15.10 I thought this had changed with a new set of non-Catalyst drivers, but the problem reappeared.

I hadn't expected this, as my previous two Dells with Intel or Nvidia graphics hadn't caused any problems since years ago when wireless issues got sorted out. Linux has made a lot of progress with hardware compatibility, but if you find one of the weird issues it can be damn near intractable and user forums are a maze to sort through.

Home built PCs are generally not a problem since they all use common, fairly generic, parts. Laptops on the other hand tend to rely more on custom hardware and solutions.