I have been flying with Porter between Toronto and Montreal every two or three months for close to five years now. Whereas just over a year ago, I would have given them five stars, unfortunately they are becoming just like all of the other airlines, trying to nickel and dime passengers for things that they previously didn't charge for.
Baggage check used to be free, and now it costs over $30 including tax if one pays in advance of arriving at the airport and over $40 including tax if paying at the airport.
I used to book a later flight and if I showed up at the airport early - which happened regularly - I'd be able to catch an earlier flight regardless of which fare I had paid. Now, they charge $75 plus tax for this option when one has purchased a "firm" fare. And yet, many of the plans still fly out with empty seats on a regular basis.
Try calling their customer service line, and you'll wait a long time. I tried twice in the last few days and waited for over fifteen minutes each time to get through before becoming frustrated and hanging up.
Porter has gone very quickly from being a fantastic airline to an average one in a very short period of time. It's disappointing, really.