In the past year, I've flown for vacation twice, with delays on one leg of each.

First one, United flight from IAD to SJU, 4-5 hour delay, mechanical issue, with updates from the gate agent every 45 minutes or so, basically keeping us well apprised of the status of our plane (and when that plane was no longer viable, of the replacement plane and then replacement crew). "Flight crew saw a warning light and needs to talk to company" then "company says try again" then "that didn't work, maintenance crew coming to look at it" then a few more similar updates. No, there was nothing we could do with the info, but it was nice to know the problem was being worked - at least made me feel less out of control.

Second one, Aer Lingus from DUB to IAD, 4 hour delay, mechanical issue, no updates from the gate agent beyond "so sorry, we're delayed another hour" every hour or so. I found this much more frustrating. No, there was nothing I could do either way, but it would have been nice to know a bit more about what was wrong, who was working the problem, etc. This felt more out of control, and more frustrating.