PHL was a disaster on USAIR. Hated going through there when I lived in upstate NY. Half the time I ended up driving 4 hours rather than waiting around all night to see if they would eventually fly. Now that I live in Southeast PA, I prefer Allentown to PHL just for the ease of access. The schedule is limited, however so PHL sometimes becomes the only choice.
Delta has been fine. One time my UBER driver screwed up so badly I missed my flight. Delta booked me on the next flight at no additional cost and even got me a seat upgrade.
Still is ;-)
DCA (Washington National / Reagan) is even worse.