It looks like there is a different amount of gap from your picture and Hannibal's but if it is more like Hannibal's I think I would consider either moving that double siding on the inside loop or adding one to the top of the inner loop at the top. It would make a much longer siding which is nice if you are trying to side longer trains or a train of passenger cars.
Otherwise it is looks pretty good, as you mentioned you may start building and decide you don't like something or multiple things and make changes.