should I upgrade to VmWare Fusion 10
after upgrading to High Sierra, would I need to upgrade to Fusion 10? Currently I have version 8.5.8 installed.
Vmware fusion 10 does feature improved support for the Realtech HDAudio sound device, allowing you to change the streaming buffer size more easily. If that takes your fancy, then go with the upgrade, but if you're content with the Ensonic1371 sound device, then nothing's stopping you from keeping 8, yet.