So you're saying that I should try "Huge" Sectors first, and see how I like that? I am a bit disgruntled by the fact that in order to play this mode, I have to do so much pointless exploring which is (in an RPG) a real waste of time. But from what you make it sound like, the game has its own specific mechanisms to make larger empires more fragile, so in the correct scenario, perhaps the game would be more unpredictable and exciting.
I've got another question though, I sometimes see these "Virus" or "Infection" races, which are like (from the description) barely sentient, anti-life species which usually only start with one planet. From the description, it sounds like if they ever established a foothold on the game, they would spread massive chaos and simply destroy everything in their path (like a virus), but since they only start with 1 planet, and have bad relations, they typically get wiped out almost instantly. Has anyone seen one of these races (such as the Talon) be successful? How did it happen?