Just to add my favorite comment:
'The world size affects'... .

how many labs ya need per tech. Smaller is faster.
Additionally, commerce income, not to mention tech-trading can be quite a boost.
When I was just starting to play at transcend level (recently in the scheme of things) I asked a lot of questions on the forum, especially about submissive factions. The AI has trememdous advantages at the higher two levels, so let it do the research for you if at all possible! Granted, turning a wily transcend AI into a submissive faction is not at all easy, especially on the larger maps, but if you manage it:
1. Keep your submissive happy: feed it tech, bases, units, anything. This way it will always give you a newly discovered tech.
2. Build up your submissive if and when possible. Just think..if that research hospital would give you 18 more labs/turn, what would it give the AI (relatively)?
3. Coordinate what techs you study with your submissive vassal if possible, and recognize that the techs it is least likely to give you are the special projects techs. It'll still give them too you if it's a happy faction, but one should prepare for the dreaded "Get back to me just a soon as I've built the Planetary Datalinks".
4. Possibly allow/influence the submissive to grow larger than yourself. If it is possible to distract the other AI's away from attacking you, there are many benefits. See some of Blake's posts about being #2 on the power graph.
5. If you are playing with pods, try to save those Ancient Artifacts for later in the game, ala when you are at tech parity with all the AI's and are ready to make a sprint for the finish.
-Smack