Correct me if I'm wrong, but doesn't the new gauge enforce more or less the exact same sequence of buttons you were doing in EW already?
Can't speak for the difference in feel between "gonna press button 5 next because otherwise Demolish will drop" and "gonna press button 5 next because the gauge is empty" yet, of course, but I don't imagine it'll be that big a deal.

Speaking for myself, I never jived with MNK mainly because managing buffs during Perfect Balance always felt janky to me, so I'll tentatively call this new gauge a good change