[eagleton]

Of the 8 races we know at the moment, 7 use rock or ice, I think. So choosing gas giants can lead to advantages because of less competition.
There are more rock and ice planets, therefore you can grow faster at the beginning, for you can construct more facilities at the same time, yet gas giants should be easier to defend because you can concentrate your forces on a few planets. Using robotoid factories and central computers is more profitable (and cheaper) with gas giants.

By the way, did anyone notice a difference between ice and rock planets?