Okay, so I'm playing the campaign, and I get a super-powerful ship, and I'm pitted against the Yor. At first, it sounds pretty simple: We're testing an uber-powerful ship. Wipe them out. Well, it turns out is isn't. I have two planets and they - well, they have the rest. Of course, I have to get the techs for taking over the planets, and they seem to research it (or already have it) at the beginning. Despite having the super powerful ship at the beginning, it just served to delay my demise. Tried several things, got frustrated. Even ended up taking over nearly half the planets in one marathon game. Unfortunately, the game took so long that the Yor were able to get far enough along the research line to make my ship useless, forcing me to invest heavily in weapons research myself. That game ended up in failure as well - I never managed to take over enough planets to turn the tide in my favor.
Ended up lowering the difficulty level to win. I must say, I'm impressed at how difficult the AI gets. I'd probably fare better in a more evenly matched game, but it does seem that the AI knows all of the standard tricks, and is difficult to fool like the AIs of so many other games.