Hola,
I’m a native Spanish speaker from Spain (I live in the U.S., spoke English all my life with a native English speaking father and my English could be better than my Spanish). Since I am Spanish, we use vosotros. While I heard people in the U.S. learn “ustedes comen”, I would say “vosotros coméis”.
Native English speaker from the US who took four years of Spanish in school: we learned the vosotros conjugations of verbs in school. However our teachers regularly reminded us that the vosotros form is rarely used outside of Spain, and that because 90% or so of the native Spanish speakers in our area originated from Mexico, we would be very unlikely to hear vosotros used outside the classroom, or see it used in newspapers/literature. I never took the AP Spanish test, but perhaps it included questions on vosotros, therefore our teachers felt it necessary to include?
This was all more than 20 years ago, so the details are a little hazy.