Well, I posted my Ascension game yesterday; my best score ever, but that was mostly the built-in score bias and not a sign of the game having been really good fun for me. It ran 500 turns, and the last 100 were pretty tedious because I was just waiting on that Ascension clock and watching the two remaining empires stew about how badly they'd be crushed if they tried to act on their anger about me ascending.
I still play on Tough b/c I don't want to fight bonuses--maybe I should try just one more notch, but I have "issues" that don't seem likely to be resolved soon. So maybe things would have been more interesting up at Painful or somesuch. But because I'm darned conservative in-game, I didn't go for even my first Ascension Crystal until I was solidly in the middle of the pack and able to keep the powers-of-the-moment fighting each other.
My Immense galaxy had only 5 crystals, 3 of which were pretty far from my core systems. The game might have been more than a hundred turns shorter if there had been another couple of crystals; five seems pretty skimpy on an Immense map.
Two other civs took crystals very early in the game, but they both ended up being crushed (I took down the Drengin, but they started it). No one made a run at any of my crystals, and I held a couple for the bulk of the game. I did feel cautious enough to lay down Military Starbases around each crystal, and I guess those augments plus the several defense fleets I kept close by might also have helped boost my score.
I guess I need to make myself try for a war win soon.