I am all for the "push-the-button" model. It is the very essence of providing service on demand rather than when the carrier thinks that it is best. Necessarily in Y, everything has to be done according to a set cadence or it doesn't get done. In F, each passenger can have what he wants when he wants it and the form he wants it.

In an ideal situation, if no F passenger wants anything, there ought not to be any crew moving in the F cabin (once soiled dishes are cleared). Conversely, there is always crew available to meet a passenger's need and that can be attended to without fanfare.