Tom,
I assume this plan links up with the other one on the first page, and if so, how do the 4 lines to the right work. Are the middle two the main lines, and the others loops/sidings/headshunts? I'm very impressed by it. I think the key to good track design is that every major route on its own looks natural.
I have one suggestion though. Adding a slip at the end of the top siding and a curved point on the inner line, so that if you're running a goods train from a siding, it makes a smooth transition to the main line. Cant remember the technical term for it, something to do with opposing curves and flange squeal!
R.