Like most frequent flyers, I don't care at all about the artificial comparisons. But one item I do take note of with interest is the rate of denied boardings.

I have a question:
The summary says that UA "posted declining performance in denied boardings." Does anybody know if this "performance" assessment measures involuntary denied boardings only, or does it include voluntary denied boardings?

Here's a two-cent comment:
If the figure includes voluntary denied boardings (in which the person being bumped has volunteered to give up their seat in exchange for compensation), then I, for one, think it enhances the overall value of flying UA. Three reasons why this probably works out well for PEs and 1Ks:
a) Higher denied boardings means that UA is flying it's ships with a higher yield, which can help decrease the overall pricing in the long run.
b) There is a greater opportunity for the most frequent flyers to take advantage of the heavily booked situations. Surely PEs and 1Ks are rarely victimized by being bumped involuntarily (I'm sure several of you have some anecdotes to the contrary). What advantages can there be? Usually being bumped voluntarily gives experienced flyers a chance to come out ahead with a few hundred dollars in compensation (in voucher currency, which frequent flyers can use most easily). If the "VDB bumpee" is protected on another airline, he/she can double-dip the miles. If they are protected on UA, it's not unusual for a harried, but grateful agent to upgrade the pax on the later flight.
c) So-called "operational upgrades" on international flights only happen because of the way UA overbooks its flights.

This is why I am glad to hear a report of high denied boardings on UA. As a Premier Exec it rarely hurts me, and sometimes helps me with a little bit of non-routine fun being a voluntary "bumpee."