I've lived in London for several years now, and lived in Paris before.
The Metro needs a bit of maintenance and rework, but let's face it, the Tube
needs to be started from scratch again. Which will never happen, since my
fellow Londoners will never admit to having an inferior network to anyonein
the world.

It's not that signage is confusing (I never had any problem with it, but
then, I'm a map addict), but some designs are very questionable.

For instance, the Paris local maps show exactly where the Metro exits are,
and what you face when you get out. In London, someone decided it would be
better to just show a big round Tube sign, and once you get out you are
totally lost as to which street is which one.

Most of the trains don't have their directions written anywhere else than in
the front. Correct me if I'm wrong, but when on a platform, what you see of
the train is not the front, but the side. In Paris, directions are on the
sides, and inside. Simple and logical.

Colour coding vs. numbers: colours are ok for locals (I tend to prefer
nicknaming the lines myself), but please note that tourists don't remember
the colours anyway.

A good point for London: everybody understand the concept of "keep right" in
the escalators. A major pain every time I take the Metro Or maybe it's
the ratio of tourists to locals, higher in Paris?

On the other hand, Londoners tend to disregard the fact that in order for
them to board a train, they have to let people off first. Very impolite, in
Paris it doesn't happen that much - but maybe it's more because of the
general crampness in the Tube, its very narroy platforms?

International signs: the RATP made a real effort in adding ES, IT, DE and EN
signs here and there. Apart from station names in Hindi in Southall and
Ealing, LU doesn't seem to care and assumes everybody speaks English. Which
is true, but it says a lot about the London state of mind vs. the Paris
state of mind.

Just my 2 pences.