I used Delta as my primary airline in 2014 and this is what I found
- Generally speaking service on Delta is better than Air Canada. This may be because my home airport has tons of Air Canada elite passengers and not so many Delta elites, but I noticed a huge difference in how I was greeted and treated on flights almost immediately.
- Having wifi on flights is amazing. I spend so much time on airplanes that this was a real bonus with flying Delta
The downside to flying Delta out of montreal is that they only fly to five places directly - Newark, JFK, Detroit, Atlanta, and Minneapolis. Typically I do visit New York and Atlanta but getting to other places do require a connection. This is especially annoying going to Baltimore or Washington where both Air Canada and US Airways (now American) fly direct. I can choose to fly direct but my experiment this year was to see if I could only fly on Delta- and I did manage this except for 2 flights.
So for 2015 I am debating whether to stay with Delta or try to become elite on American, as it is the last major alliance I have not tried... anyone have thoughts on this?