We flew Porter to Chicago a couple weekends ago and, man, it's by far the most romantic way to travel. From the WALK to the airport, to the 1.5 minute ferry ride (which apparently holds the record for the shortest ferry ride), to the tiny 50s-esque planes, to their actually fairly decent food, it's just a pleasure to travel with Porter.
Only two issues (neither of which I've actually experienced first hand).
1. Parking is super expensive (but, hey, what do you expect for a downtown airport).
2. Delays or cancellations are more common because the planes are tinier and less resilient in crumbier weather.
Other than that, love that they serve Steamwhistle (Toronto represent) and love all their branding. I feel like Porter is single-handedly trying to edge is away from North America and make us a little bit more Scandinavian.