My review is based on my experience with UP Express after their price cut.
From Pearson Airport to Bloor Station for $5 with my Presto Card?! This is quite a bargain. This is a good option if you want to get on Bloor Subway line without going all the way down to Union Station.
The ride was fast and smooth. Rack for luggage, Electric outlets at seats, Free Wifi. If I am a tourist visiting Toronto, I would be so impressive! A Metropolitan City our size should have an Airport express train.