Was on UA1582 yesterday (Dec 24) from TPA to EWR. Original aircraft was put out of service due to maintenance issues after multiple delays and we flew to EWR in a replacement aircraft, arriving 6 hours and 35 minutes late.
We were all in first class - 2 RPUs used to upgrade parents + myself as a 1K who was CPU'd. Given the delay, nearly everyone else had already switched flights while we had stuck around since I wanted to take my parents at least once in their lives in first class - the 737 ended up flying with just 9 passengers and 5/6 crew!. Supposedly the lowest number of passengers they have ever flown a 737 for - EWR gate agents were in disbelief when we deplaned. They ended up seating everyone in first class anyway given the number of passengers, so the treatment wasn't the special experience I had hoped for my parents and a waste of RPUs given that everyone sat there anyway and all boarded at once.
The appreciation website automatically provided me $125 e-cert as a 1k and parents $75 e-cert each with no status. I found that a bit low for being in first class for over a 6 hour delay on Christmas eve, but would appreciate any thoughts on whether to pursue further, especially given the RPU experience (but all booked in economy). The pilot told our family it was a miracle we were flying to begin with given the number of passengers left, otherwise we'd have missed Christmas day entirely, so glad it didn't come to that at least.