We've flown SWA almost exclusively for the past six or so years from PHL to MCO and have never had an ontime problem flying from PHL/MCO, except one instance when we departed ontime, but, got about 30 minutes into the flight and needed to be diverted to BWI due to a mechanical problem. However, SWA was excellent about it........we were unable to continue on that particular equipment, but, another flight was due in within 30 minutes of our landing and scheduled to remain overnight at BWI. They just transferred all the baggage and had us onboard the other plane and on our way again in about an hour or so......pretty scary being diverted and all......landing with firetrucks waiting for us, but, it was handled very well. However, on the return trips from MCO to PHL.......we have been delayed far more than ontime. We once heard from someone in the airport/airline business that the majority of delays caused in the northeast corridor is due to the sheer number of flights in to and out of the major airports located in such a small airspace area (both NY airports, Newark, both Washington airports, plus Baltimore and PHL)