We give SWA and the other airlines 75% off regular rates, but when we fly interline they take 75% off their highest rate, making it less of a deal than it seems.
That said, some FedEx people do act like idiots when they fail to realize that they are standby passengers. I've been in my seat on a SWA airplane getting ready for pushback and asked to get off the plane because a paying passenger showed-up at the last minute. That's just the way it is. Other times, I've waited for 5 or 6 flights and had to go home because there weren't any no-shows.
I'm not sure what airport you fly out of MrFedEx but I'm glad to hear you use the travel benefit. Its my favorite part of FedEx hands down but you gotta be good at it.
I often use Flightstats.com "Seat Availability" tool to figure out the 'likelyhood' of me making a flight. If there are 6+ seats you'll most likely make it.
If you're flying jetBlue call out as far as you can to list standby. Globaltravel won't tell you (but jetBlue will) that you can list for their flight as early as you want to (I think its upto 90 days out). Also, call-call-call. jetBlue crew support is always incredible when I talk to them. Sometimes they won't tell me the numbers, but they will make good suggestions (like if I'm flying from Boston I sometimes hop down to JFK for a better chance). I have yet to miss a flight with JetBlue. Infact one time they asked a pilot flying coach to fly jumpseat when they found out I was with FedEx.
I, however, have been bumped from flights. The worst was an AirTran flight where they told me to go on and find the one empty seat, I looked around and didn't see one, then the flight attendant asked if I was non revenue. When I said I was she walked me to the jetbridge and asked me to wait and slammed the door in my face. Talk about disheartening. The plane just backed away without me.
A LOT of People at Express don't use the flight benefits, I feel like its one of those things that makes FedEx worth it.