YX is a great airline. The people are very friendly, and they are the only airline that bent rules for me on itinerary changes when I wasn't even remotely close to elite. When I lived in Milwaukee, they were a good choice.
My only complaint is that I'm not fond of DC-9's and MD-80's which are the only aircraft they fly... but I have a feeling I'm opening up another can of worms here. It's just a personal thing I guess.