geez, i dunno.
i travel EWR ---> HKG four or five times a year, with onward travel within asia on CX - and many of these observations - said with great certainty - don't align with my personal experiences.
UA agents definitely clean bathrooms, or at least i assume they do. i've used the loo in hour 14 and 15 of these flights and they are always clean. in particular, i've noticed that debris and spills that were there earlier are no longer there and there's usually plenty of room in the waste container.
the cabin is as clean as any other airline, in my opinion.
as for aisle access, if you care enough about this (i do) and book early enough, it's pretty darn easy to get direct aisle access in the center section.
as for food, the polaris menu is pretty damn good, albeit a little rough around the edges, with service varying from flight to flight. i can't compare it to CX, because i haven't flown this route with them in over five years, but by many accounts in this thread, CX food has declined while UA's food is generally much better than it was. i suspect that many of the folks who say CX has better food on this route may not have any recent experience with the polaris menu EWR ---> HKG.
lounges? not even close. CX all the way, especially in HKG.
i don't drink coffee, so i can't comment on the availability of espresso drinks (or lack thereof). if this is especially important to you, it sounds like CX is definitely the way to go.