Yes I have, twice. EWR-ORD and IND-EWR. Both because of weather. Told long in advance it was going to happen. First then general boarding for everyone. Pushed back 10 minutes after boarding started both times w/ full 73G both times. Airborn in 15 minutes on teh IND-EWR flight so we were in the air before ATC could tell us to return to the gate because of traffic at EWR.