There's definitely a few people that voice their opinions about it, but the majority of them don't really care.
I think regardless of what flag gets chosen, people will still use the old flag and it will take literally years before flags get updated on websites, or it will get completely ignored and we'll end up reverting back to our current flag down the track.
Another thing to note, is that we don't have the same level of Patriotism that America has. You don't see NZ flags wherever you go, maybe outside some government buildings, but it is rare to see a flag in a residential area in someone's front yard.