The skylight refurbishment is actually quite nice, and is more than just ensuring that Union Station doesn't fall down.
I wouldn't mind a paired-down scheme, keep the upper Great Hall the way it is (but finish the refurbishments), and redevelop sections of the rest, like the old CN/CP offices, particuarly the abandoned west wing, or the lower level with retail, like an upscale-looking food court, like Halles de la Gare in Central Station.
The GO Concourse needs a redo. Very very badly.
Under the broken clock in the centre of Union Station stood a sad German tourist. Antje Heinen, an engineer from Munich, had trekked to the station for guidance on points of interest in the city. She found the Travelers' Aid Bureau below the clock with a sign on it: "Sorry, the booth is closed."