I upgraded only one system so far.. and have ran into serious audio issues across the board.
Creative's Sound Blaster Z card goes from 5.1 to 2.1 sound... and a bunch of other system wide issues with audio.
However, it's affecting VLC in a strange way. VLC now opens with the volume at 0. Using the mouse only allows an increase to 5%, and nothing more.
I tried the only work around I could think of... (and this is currently with only Windows default sound drivers).. is to go into Preferences, Audio, and set the volume box to stay at 95%. If I don't leave that checked, closing VLC reverts the sound back to 0 upon a new start up.
Just a heads up for those heading into 1809... as it may happen to those using that sound card, or if there's something more troubling with the 1809 sound subsystems that were modified by MS.
When it works.. they just can't leave well enough alone.