DP4 is stable enough to use on my production system. Yes, I know never to put a beta on a production system but anyway, it's working now. I'm glad the DPs are going to be updated more frequently (or so I read).
I put DP2 on my 2012 air and within an hour I'd gone back to Mav. When DP3 came out I tried again and stuck with it as I had no problems. I've upgraded the Air to DP4 and have now installed DP4 on my main iMac. Zero issues.
Just partition your drive or boot from external drive. DP4 is very stable there shouldn't be any MAJOR problems for use on main computer.
Couple questions, how can I download it to an external drive and then how do I boot from that drive?
In the installer, select the hard drive as the destination. To boot from it, press option on startup and select the drive.
I can just go back to Mavericks if I encounter any problems can't I? Guessing there will be support from Apple on it?