In my last game I played a DL 1.2 gigantic map, everything abundant, loose clusters, very fast research, tech trading enabled, on level suicide against 9 AIs.
In my current game I'm playing DA 1.6 medium map, common stars, occasional planets, normal research, tech trading disabled, on level suicide against 6 of the best AIs.
In the previous game (just like earier games) it was a race to grab the best planets and galactic resources before the AIs. I kept taxes low to keep my morale at 100% for maximum population growth, while I grew my morale and economics. I funded my colonization phase (lasting ~1.5 years) with money anomalies and tech trading which also allowed me to keep the tech lead. Then I switched to researching weapons, advanced hulls, and logistics. Then started building a military, while a researched the planetary invasion branch. Then I started building troop transports and when complete went to war with my nearest weak AI player. I did this repeatedly with each AI, most wars lasting only about a month.
In my currently game the colonization rush ended quickly with so few habitable planets (except for the extreme planets). Without tech trading, the Ultimate AIs were able to grab the extreme colonization techs before I. Also, without tech trading and without 2500BC money anomalies, it was much more difficult to get my economy in the black with maximum production and espionage spending. Also, since the AIs in DA 1.6 are much better at developing their planets, I was far behind the AIs in research and in building a military. In order to keep them from declaring war on me I bribed them to war with each other. I used economic/research treaties and money to bribe the Drengin and Korath to declare war on the Altarians, forcing the Drath and Torians to come to their aid (the Thalans remained neutral). This game is playing much differently than my past games with me on the defensive! I picked first strike as my super ability but I'm basically playing the role of the Drath until I'm ready to go on the offensive with fast high attack fleets combined with Eyes of the Universe.

Sadly, I don't see the Drath making this use of their super ability and they are not spending enough on research.