I usually play the game with lots of planets ("abundant everything"), and I get the impression that most of us play that way. For some variety, I decided to try the complete opposite. I went to the largest map size, made everything rare (except asteroids & anomolies, made them abundant), with the most races possible (including maximum number of minors). It made for an entirely different kind of game, and it was lots of fun. Technologies that I generally ignore (like life support) all of a sudden became important), given the vast distances I had to travel to even meet someone. There was no "colony rush" at all. My colony ship went to my "Mars" and that was that. The first part of the game was, instead, more of "build my economy, hunt for resources, and try to find somebody else out there."
One lesson I learned the hard way: An approach that works with one type of setup may not be so hot on another. I usually play with the Torians, taking advantage of that great population growth to get a strong economy. Uh ... that doesn't mean so much when you only have two planets. After getting my butt kicked a couple of times, I finally realized that my race's "super ability" was only helping me for a short time at the beginning of the game. I changed over to Korath and made use of those great spore ships. Also, I could not afford to downplay the importance of diplomacy the way I usually tend to do. Having seven or eight major powers all declare war on you at once can really ruin your day.
Anyway, playing this way got me to thinking that a lot of our discussion here ... about play balance and which is the best strategy and which racial ability is the best ... all of this is to some degree relative to your game's original setup.
And, this variety is part of what makes this such a great game.