Ironically, I flew into PHL last night (on Express) and my bags didn't show up. I don't believe it was their fault though--I had a 36 minute mainline-to-Express connection in LGA and think my bags probably didn't make the connection. I must be really lucky or something, as with all the flying I do, I've only had US lose my bags three times ever, and I do check bags the vast majority of the time. And it was PIT's fault twice and now LGA once, and that's with almost half of my flying beginning or ending in PHL. Each time, though, US has delivered my bags the very next day, including this time, so it really doesn't bother me much at all, I fully understand that sh!t happens.
To continue with the positive nature of my thread, the lady who took my bag claim in F in PHL last night was very friendly and apologetic. Not that it matters, but are the BSO agents in F in PHL Piedmont or mainline?