Right now, there are monitors displaying the arrival times of various trains right next to the tracks, and on the mezzanine levels near the turnstiles. However, there is no monitor at the entry to the station. Thus, when you're arriving at the station you have no idea if the next train comes in one minutes (so you have to run down the escalator and buy your ticket extra quickly) or if it comes in ten minutes (so you can just wait on the escalator and be more relaxed about buying the ticket). Just by moving one terminal to each station entrance, you could substantially improve the quality of life for everyone arriving at the station, at least by relieving anxiety during that escalator ride down.

(Of course, this all depends on the monitors showing accurate times rather than scheduled times, but 90% of the time the actual time seems to be within a minute or so of the scheduled time, so that distinction doesn't matter too much.)