CSeries would make complete sense - more fuel efficient than existing A319/20s and plenty of delivery slots available. With the impending Airbus JV support and favorable experience from SWISS adding the CS100 and CS300, it just makes sense for Spirit to seriously consider it.

Bottom line: the CS300 would be a great growth platform for Spirit in all market types (including secondary markets) - even Air Canada recognizes the benefits and will be adding 45+ CS300s starting in 2019...