I've reworked area around Bank, Liverpool Street, and Moorgate
implementing multiple suggestions - not sure if the map became nicer,
but at least it is more realistic now.

Also, I changed the District line beyond Barking - it was too curved.

And finally, I created a dedicated web page for the map (and future
versions and weekend updates):
http://www.fxfp.com/lib/tube/

:-)