Roland Perry writes:

In message
-sept
ember.org, at 08:03:57 on Thu, 28 Apr 2016, Recliner
remarked:
Probably not double (have you seen how few people use the T4 station?), but
more certainly.

Latest annual station usage stats:

T123 7.49m
T5 3.90m
T4 2.35m

T123 serves 3 terminals, so assuming it represents equal numbers of
passengers using each terminal, there is not much difference between
2.49m passengers using the station for access to each of terminals 1, 2
and 3 and the 2.35m who use the T4 station.