From the photos Bren it appears to me that you are building the layout with a view to having an actual model of a real working railway. The one thing we all wish for is space, and unfortunately for a lot of us that is not a luxury that we can avail of. You are making the most of the space available to you, but it doesn't look cluttered like some large layouts can, and that is the reason why it is looking right. Some of the photos remind me of Sheffield in the 80's. There is the luxury of being able to run full length trains and shorter trains. When a train disappears off the scenic sections it can snake around the non scenic or viewing angles to appear again at a later time, and that will give you the opportunity to run the trains to a timetable, thus making it a lot more interesting. Running stock from different era's is a great way to keep things interesting also. You can have a steam era running session one day and a more modern era session another day without things not looking out of place.
I am really enjoying watching the progress, and I know why Young Fran is a frequent visitor. It looks like a great layout to let a loco stretch it's legs, and better than any rolling road to run in a model. The ballasting should be fun, and I can see a few Superman poses when carrying out the work, not too unlike the last layout. Can't wait to see more updates.
Rich,