Stable enough for day to day use?
Yes, i'm running it on my main work machine.
I did a clean fresh install and manually transferred my files over from my backup. Apparently there are bugs / issues with upgrading, and it generally doesn't run as fast. No problem for me because i've been meaning to start fresh for a while now.
The only issue I have is that VMware fusion doesn't work in unity mode, so I just run it in windowed mode in its own space.
Its lightning fast, no lag at all.