When I set out to build my Waverley East layout in our last house I had visions of 10 coach trains hacking round a decent run - I did after all have 36' x 11 and Gilbert very wisely as it turned out counselled me to wards keeping it simple, especially if I was planning to turn it on my own.
As you'll see if you can be bothered to trawl through the 20-odd pages of drivel in my own thread, this actually got to the building of the main lines and fiddle yard, and the setting out of the main station. I realised that operation was going to be way beyond me, and in fact with my eyesight getting slightly less sharp I found I couldn't really see much of the long train in the distance - The length of my room meant that a train at the other end of the room is a scale half a mile away, so all detail, even the number on the loco side, gets lost.
We moved a couple of years ago so the railway had to be dismantled, and my new room is 21'x9'6. That is much more manageable, and while I will continue to have a very complex engine shed and a six road station to play with so I can terminate trains to send them off in the opposite direction, complete with loco change, I'm eschewing a fiddle yard in favour of semi-concealed storage loops so trains don't have to go round lots of times. The theory is that I should give myself a lot less of an operational headache.
IN fairness I'm not massively enthused to get on with it at the moment, partly due to injury and partly due to having got a bit disillusioned at the last line by biting off too big a mouthful!
There's a reason most layouts never get finished - ambitions are often much larger than the practicality. In that respect layouts like PN and Little Bytham are unusual, but they serve much more as a backdrop to the owners' main interests - in Gilbert's case realistic operations and Tony as we all know is an amazing builder of models.