We recommend installing OS X Yosemite Beta on a secondary Mac- Yosemite Installer
Upgrade Complete! Who cares about warnings? I've upgraded all of my computers to OSX Yosemite Public Beta -- including my work computer. My company's IT department gave me a dirty look when I mentioned I was a having a couple issues. It went so well I upgraded my iPad to iOS8. It went so well I upgraded my iPhone to iOS8. Good decision? Or GREAT decision?
Back in the day I was always running 3-4 OS'es on my computer, beta versions of a dozen different major applications, and it was glorious. Somewhere along the line I ended up wanted stuff to just work? Maybe it was at the same time as my move to Apple, or maybe it stimulated my move to Apple. All I know is that recently I've been running Chrome Developer version and the Webkit nightlies and I figured... LET'S DO THIS!
I'm not crazy - I did full backups. Realistically 90% of my job is done through cloud services and the last 10% is backed up onto Google Drive and Dropbox. If my laptop was destroyed tomorrow, it would have almost no impact to my productivity. So - upgrade away! From time to time my laptop goes into Kronn Hunter Mode ala Area 51, but that just makes it's cooler.