Since installing the new patch it has appeared to me that the quality of the map is massively reduced, there is no sharpness to it, it appears blurred and landmarks such as mountains and rocks appear as simple grey shapes rather than more distinct things. Anyone else agree?

Okay it depends maybe on the different locations, but for me i don't see any significant drop in quality.

Maybe some locations looks better than others, but the landmap is so waste that somebody will have difficult time to remember each locations.

Is it cloudy? Then your map will be indistinct. Try the Clear Skies Shout (at least it seems to clear the clouds from the map, just make sure to wait until they clear from the game)

not so much cloudy as it just seems really blurry and quite pixelated