Do Forge of God/Anvil of the Stars differ significantly from pretty bog-standard dark forest scenarios?

I don't remember any other of his books that might apply, but I haven't read all of them. (I probably should. What I have read was great.)

"Dark forest" doesn't work from a game-theoretical standpoint. It assumes that it's cheap to destroy entire planets and solar systems. Yet no-one seems to be colonizing other systems.

The optimal strategy in this case is to expand as quickly as possible, before others can grab or destroy resources.