I've had fantastic medium to medium-rare filet on AF in business. Nice medium beef on NH in F, etc.
I don't order beef from U.S. carriers. They always kill it. Maybe it's this notion that it can't be done better (as we've seen posted above). It can be, but it isn't, at least in my experience.
As to the topic of this thread, UA Global First is a joke. I had the (dis)pleasure of flying UA GF from ICN to SFO after SHARES dropped my CA F segment, and was served this as the main meal: