Dave Arquati wrote:

Oh yes... the frequent and widespread train network in South London
makes it extremely difficult to get anywhere, not to mention trams
and
buses... :-)

Quite so - some colleagues look at me as if I've just arrived from Mars
when I tell them it takes me less than half an hour to get from home
(West Dulwich) to desk (Farringdon) - a journey which doesn't involve
the Tube at all :-P

Perhaps that's a Tube map mentality, which might be partly resolved
when
the Overground Network-style maps are combined better with Tube maps.

[Serious thread-drift now] I think this is likely to be the principal
(illusory) advantage of the ELLX, if it ever happens - i.e. not
"improved access to Central London from Crystal Palace and Croydon"
(which is clearly nonsense), but the positive effect of names like
Crystal Palace and Sydenham appearing on a Tube map for the first time.
Assuming it will be shown on Tube maps, that is.