My work PC updated no problems, all done in about an hour...
My home PC, however!, Took about 4 hours, and Windows has cleverly 'hidden' most of my app shortcuts from the start menu! It looks like a common bug, and Microsoft have acknowledged it's existence! One Bug fix they say, is to 'Open the Windows Store, and search for the app you want from the list of 'My Apps' and launch it from there!' all well and good, but the Store is one of the icons hidden from my start menu! I can't even find is when I search with Cortana!!
They've said there will, probably, be a bug fix in the cumulative update in a few months!!! until then it's put up, or roll back!