A couple of nights ago I installed the 2015 standalone installer on Windows 8.1 a VMware VM. That went perfectly and the product just worked fine.
Today, after the VM testing, I installed 2015 on my host workstation (of course choosing Custom Install and all the options I prefer to use). Again, this was an extremely smooth, quick operation, with nothing unexpected, and a very nice surprise - virtually all my settings, including a custom scan, were retained.
System benchmarks show my system to be performing at nominal levels.
All my applications work fine.
Software Updater says everything's up to date.
All systems go.
Thank you, Avast! I couldn't have hoped for a better experience.
-Noel