We just flew them two weeks ago to Florida and back.
The positives - they got us to our destination and back safely and pretty much on schedule. The outbound flight was actually early and the return flight was delayed only about 15 minutes. But that was not a fault of theirs. They did a pretty good job of keeping us informed. Complimentary drinks were offered.
The negatives - I have never been so smushed in a middle airplane seat as I was on our outbound flight. I don't remember what kind of plane it was, but it was VERY tight. And I am 5'6", 140 lbs. In fact, I commented to DH when we got on the little puddle jumper for the second leg of our outbound trip that we had much more seat room in the little plane. The United flight attendants were not at all welcoming or friendly. They seemed to want to be anywhere but there. I thought maybe that was just my impression, but when we boarded the puddle jumper, there were other passengers from our United flight that were commenting the same thing. The flight crew on our flight back was much better. Also, my middle seat on the return flight seemed to have a bit more room.
Now I know my negatives can be found on any airline at any time, but it didn't leave me wanting to make United my first choice airline. We were happy with Continental before the merger. Oh well, I know times change, things change and they have to be more economical. But it doesn't cost more to be cheerful, friendly and welcoming. I may still fly United because of times and cost.