This is, I think, the first time I've ever had to ditch a beta.
Using OS X 3.9 on an iMac -- It's extremely slow to load, when it does load the online icon greys out and can't be brought back to online using any of the options. If I quit and rebooted, it sometimes would go green, but not for long.
I also couldn't reach the skype test call -- it would hang on "connecting" with nothing happening.
I could get to chat...but only very slowly, and once in chat could not make a call.
Overall, it seemed to be dragging horribly - typing/clicking on menus etc -- all almost in slow-mo.
Soo..for the time being, I'm back to the non-beta version ......