As a fellow ex-ual elite member who pays for F, I can assure you that VX staff are vigilant about who puts stuff in F as well as maintaining MCS seats. Pax rarely try to sit or put stuff outside of their seats. They're trained that they can't get away with it. I've been on "full" flights in f and Mcs where the only open seats were in my row.

Adequate staffing makes a big difference. Oh and when in F, enjoy your PDB that will be offered :-)

I still can't get over people who prefer UA F seats over VX F seats.

And I definitely think VX is way better than AA