I have been thinking about using a system other then D&D 3.5 for the Birthright campain setting. The one I've thinking about using is the Game of Thrones D20 system, which is similar but does not have a magic system and fewer hitpoints, making it significantly grittier. Before I jump into this I want to know what were other people's experiences with different systems in the Birthright world? What works well in your game and what were the problems? Any insight would be helpful.