If I'm in a Lib race I like the GM for golden ages just after Lib. (anyway, winning a Lib race with Izzy is hard enough in itself) But I shall try it one these days. I do understand that it has possibilities, but it are possibilities not suiting my usual game plan. The sound of heavily promoted siege is pretty nice, though. It's really one of the best bonuses, but just on a weaker building in itself.