If your "jam-em-in low-cost with 3 destinations or so..." is WestJet, you should know they now service 21 destinations (with more being added all the time) and are very close to being a coast-to-coast carrier.
Load factors have always been high, but they are getting higher due to - surprise - an increase in business traffic.
Most important (both pre- and post-September 11), they are one of the few airlines in North America making a profit...