Thank you danes. Thank you. Thank you. Thank you.
RogueHyena
It appears the best defense is a good offense. You're absolutely right, I've been doing the same thing after figuring out that the defenses require a lot more space to block an equivalent damage in offenses. Plus, the really good offenses (nano-ripper, for example) come earlier than the solid defenses. This is the obvious problem with combat not being simultaneous, thank god the AI doesn't do the same thing.
Major help with research, a little help with the economy and a little help with soldiering. I never seem to bring enough soldiers for any big invasion, so every little bonus there helps. "Green thumb" I find also very very useful for those dull planets.
It worked just fine for me, but it considered the game to be "normal" when it was a few notches up. (felt robbed) Either I screwed up, or it defaults to a new normal game. Just in case, I'm not going to risk it next time.
I'm going to go out on a limb here, but it's totally Hyperion Logistics Centre. That thing just turns the whole game around for me.