I had a similar experience with Sunwing myself. I left Montreal on Feb. 12, 2010 on a 4:35PM flight that was to arrive at 8:15 in Cancun. Pre-boarding we were informed that our flight was being diverted to La Romana, Dominican Republic (for anyone who knows geography, DR is in the opposite direction of Mexico!!). They only boarded us at 4:35, at which time we sat on the plane for well over an hour to wait for Sunwing to receive parts for a plane that was stranded in DR, and for the mechanics to arrive. The flight to the Dominican was well over 4 hours - when we landed in the Dominican we were told to get the parts off the plane and to de-board the mechanics was going to be quick - well, we waited in the DR for over 45 minutes. Finally we were on our way to Cancun - another 2 HR + flight to Cancun. Needless to say we arrived in Cancun at 1:30AM Cancun Time (what was still 2:30AM EST for all of us who clearly were still on our own time zone schedule). We arrived at the hotel at 2:30 (3;30EST). Over 9 hours on a flight with my 3 year old son and my 77 year old grand mother who had arthrities in her legs - yup our first day in cancun was ruined due to fatigue and pain. I must say that the staff on the plan were great (especially Steve and Malane), BUT 9 hours of an angry flight, people walking up and down the plan (especially to the back to go to the bathroom, close to our seats), was not only annoying, and uncomfortable (due to having someones butt in our face half the time), but after 4+ hours, the stench of the bathroom was quite nasty. Yup, we too got the really lame "we're sorry, " which was not at all sincere - in fact they tried to play it as "we're on a rescue mission, yay us!" YEAH RIGHT! I paid for a direct flight and got a 9 hour flight that passed through a country I had 0 intentions to go through. Had I wanted to ruin my sons scheduled, I would have taken the 9:30Pm flight that left Montreal (which just so happened to arrive in Cancun before us), and saved myself quite a bit of money. Thank you Sunwing!
On a side note - isn't it a bit scary to read how often their planes are breaking down?