It would work well for me, living near Belleville, and flying out of Pearson:
Via rail to Union station
Union station to Pearson via the new rail
No parking fees for a couple of weeks, no driving thru gridlock, no sardine crush on the ttc, no stale limos snaking thru traffic.
It's seamless, and a perfect way to begin and end a vacation. Drinks and downtime on Viarail as well...perfection
It's not always about what works best for you Trawnna dorks. In the bigger picture, it's great for ontarians who live east of the city and don't mind spending an additional $200+ to their trip cost before even getting on a plane.