EK without a doubt. Though I m not familiar with all the problems over there I doubt it could be worse than the life you would get on the 320 at EY.
Ey 320 rosters are a joke. Lifestyle in Abu dhabi is certainly not bad but most people prefer living in Dubai.
regarding upgrade time, it might be lengthy based on current amount of people upgrading every month. however I doubt it will remain constant in the coming years. I could be completely wrong though.