I have an AMD ATI R7200. Upon finding the proprietary driver not being available in 16.04, I was initially very disappointed. Particularly so, given that pre-16.04 the opensource driver was pretty rubbish. That is to say, it had a very limited set of resolutions available and also the colour used to always look a bit "washed-out". Most crucially, it did not utilise the open GL capacity of the GPU, which is essential for effective compositing and the reduction of screen tear when playing games or movies.
However, the Linux world seems to have upped its game with the AMD open source driver in 16.04 as a consequence of the propriety one not being available. The selection of resolutions is large, the colours are now bright and vibrant and, most important of all, GPU hardware compositing works.
Of course, all of the above is based on my own personal experiences. But, I thought I would share them, for what they're worth.