I installed Designer Schematic on my 8.1 machine. I did not have any problems during the install or the last week or two of usage.
I did get a prompt saying a reboot "may be required to finish the installation". I did reboot although I don't think it was needed.
I did not use any of the Win 8.1 Compatibility settings.
I have successfully imported designs from OrCAD prior to versions 16.3, made and imported symbols and used them in a design, wired schematics and most other functions
without any problems.
I have left the program running for several days at a time with no issues at all. The program is very stable and does not use up to many resources.
I also came across a feature by accident. You can detach the tools bars by left clicking on them and dragging them into the schematic window
which turns them into floating toolbars and gives you a little more vertical space. Right now the toolbars are horz orientated.
Not sure if they can be rotated vert? but that would be a nice feature
I will try to post more and upload my machine specs and preinstall log files. I wanted to get this posted for now.