Having recently acquired and set up our two new PCs with Windows 8.1 I have inevitably had to install numerous updates. Looking at the optional updates I note that there are pending updates for graphics and audio drivers. In the past I have never bothered to update these drivers but I do wonder if (subject to checking that they are definitely applicable to my setup) if it is preferable to accept these updates if the PCs are running OK.
Incidentally, both machines downloaded and installed 8.1 update 1 quickly and without any issues.
You could always read the changelog and see anything stands out as making it necessary.