First, thanks for buying SS4!!!!
As to terrain, I like a crowded board, if only for the fact that super-strong models can wield a lot of objects as clubs or make-shift missiles! So having cars, lamp posts, mail boxes, etc. makes a game more fun. The super-strong gal can't get at that annoying flying model? Sure she can! She just tosses a mail box at him!
Always remember, +1D defense for soft cover, +2D defense for hard cover, and you get cover so long as any part of your base is obscured by it.
Hope this helps!