OP -let's put it another way... Had the flight operated on time...was the rest of the UA experience more or less as you expected? Would you do it again if you knew with certainty (which is impossible, but this is hypothetical) that the flight would operate on time?
I can't really say for sure since all of my negative feelings come from the fact that it seemed so commonplace to frequent flyers and to gate agents that there would be this massive delay. And, for me, timeliness and low-stress accommodations were my top priority in booking this flight. I only have one data point, but based on the collective expressions of other people on that plane, I am led to believe that ontime performance and resolution of delays would be more straightforward on US on average than on UA, especially once you add in status.
Things united did well: they offered meal vouchers, free IFE, once things went awry. The FAs held together pretty well and didn't take out much angst on pax.
I know people who are loyal united FFs. I have contemplated trying to get status on United but in agreement with what people say on the boards, it really is a much tougher world even if you are an elite on UA. And I am saying that in terms of an upgrade list 50 people long, 1Ks being stranded with the rest of us lowly folk, and so on...