Stephen, was it as "complex" as RftG? I thought that game was kind of heavy for a lot of my gaming buddies that are into quick light games. The art I've seen so far for Imperial Settlers makes it look fairly accessible, but is the game accessible too?
I didn't find it nearly as complex as RftG. Let me clarify: Imperial Settlers is much easier to explain. The iconography in RftG is hard to get through (although worth it), but the icons in Imperial Settlers are much easier to remember. You can teach the game in 5 to 10 minutes. It also has a defined number of turns, so you don't have the strategic aspect of pushing the game to an end condition when you are winning.
I think how heavy the game is depends on which variant you play. If you play with the standard rules which allow other players to raze your locations, then the game can be complicated. You can't just focus on building a streamlined engine because someone will sabotage it. On the flip side you have to pay attention to everything else that is being built so you know when to strategically disrupt other players. If you play the variant where you can't raise other players' locations, the game is a much lighter game where you are trying to optimize the cards you draw.