Been working with 8.1 installed on Windows 10 Pro Technical Preview. Just wanted to throw out there so far its running much faster on Win10 then Win7. I have it installed on Mac through Parallels and it seems fine so far. I genarlly have a few things I look at to compare speed and those for the most part are a bit faster. I will do my best to get it to crash I seem to have a good knack for that.