(a) certainly A few years ago (more or less right after the merger) I was in MSP waiting for a MSP-ORD-CLE. While the MSP-ORD was showing as "on time" I was tracking the inbound AC and saw it was due to arrive MSP +38 after the outbound was to depart. With a 45 minute connection in ORD I knew there wasn't a chance in heck of that connection working no matter how fast they got everyone off, cleaned, and on.

Talked to a gate agent who agreed it was an issue and started looking at options -- again this was just after the merger and he was very obviously a pmUA employee not quite with his SHARES feet under him yet so I did a bit of prompting and he did a lot of "what do I/how do I" to his colleague next to him who was either a pmCO or a pmUA with more SHARES experience... While this is going on, there's some radio chatter that I'm not really paying much attention to but sounds like a bungled version of my surname and a few seconds later a new agent jogs up "Is this Mr. LincolnJKC" "Yes" "Run with me." We jog a few gates down the concourse and she pushes me through an open jetway door "Just take any available seat, we'll figure out the paperwork later" -- as they're closing the door behind me "...19C should be open"

I get to 19C put my bag under the seat and ask the woman next to me "This flight is going to Chicago, right?" She looked very confused/concerned, answered in the affirmative and I made it to Chicago with plenty of time to make my connection.

I figured just to be safe -- since I never even had a boarding pass for that flight -- I should visit the customer service center to make sure my seat was intact for ORD-CLE. It took them a few minutes because as far as they could tell I was still in MSP

One of two very tangible times United has gone very far out of their way to take care of me as a customer (the other was indirectly me but as a favor while my wife and her dad/brother were traveling for an impending death in the family and I was unable to get back to the US in time to join them)