Hmmm, VX coach is superior to UA and AA in every way except for legroom in E+ and that is offset by the paid access to exit row seats. So for coach VX is a no brainer. As for F, we don't know how VX will compare but UA and AA service is so bad (including the outrageously priced PS) that it is hard to imagine VX will be inferior and certainly will be a better value pricewise for the vast majority who pay to upgrade (unless you are one of the fortunate top level elites who can upgrade these routes for free).

Over the past 20 years of flying I have also had pretty good luck with getting FF seats in Y or C to just about everywhere I wanted to go at the times I wanted to go (including summers or holidays). However, the whole blackout of advance saver inventory for XC on some of UA's most popular international routes has left me with a lot of resentment (and your point about the phone agents, nee ICC, is well taken).