Fair dinkum, the further along, another quiet voice (yes, there ARE alot) started questioning if games could be played.
I completely understand where you are coming from. My idea is that there are basically 4 different zones to the board, the slums, Industrial, Aeronef Port and Market Highstreet. Each Zone can then be used independently for small skirmish games with a mini-campaign of 4 games covering the entire table by the end. I have also kept the taller buildings away from the centre. It's a bit deceptive when you look at it but the actual playing surface is very accessible whilst standing around the table.
I wouldn't want to make the layout any bigger that's for sure as it would get hard to use.
With the base tiles all being modular it can also be broken down into a 4' x 4', which is probably a better size for my Fantasy buildings as I have less of those. It can actually be made even smaller than that and I have plans to use a simple flat 4' x 4' section of basic flagstone tiles as the base for my Gangs of Rome set-up.
That will have to wait for a while though as I have a rather large 6'x15' project to work on now.