After playing the last two beta versions, I love some mega events and think others need tweeking or eliminating.
-Good: recession (having both good and bad economic times makes for interesting game play and political/military opportunities), plague (research the cure and trade it), increased tourism (targeted and useful)
-So-so: things like increased ship speed or range, because they are universal, don't really affect gameplay that I noticed
-Bad: spy mega event (okay, let's kill this one. For a gigantic map mid-way through the game, the number of spies I have to create to nullify the 40 or so spies planted on my planets is prohibitively expensive. It takes years to clear them all.), political discontent (this one is okay for a while, but it happened early in the game and has not gone away. A time limit on this would make it better/more realistic.)
-I'm sure there are others I haven't seen yet.
Overall, shorter timelines on all events and a better mix of beneficial and harmful ones would really help shake things up and keep the game interesting.
I'm loving DA, even more addictive than CGII, if that's possible.