Which one is the most stable version for first time working on Ardour?

Would I use 2.8 or Beta 3.x?
I want to work with relative calm to continue supporting Ardour, because I’m looking for a new DAW, no Protools anymore! I’m on Yosemite, is the best OS until now, my soundcards sound the best and Macbook Pro’s performance is so sweet.

If starting from scratch, grab a nightly build of 4.0 and try that out at this point.