Well, I'm not going to argue at length over the red ribbon, since it mostly comes down to personal aesthetic taste of course.
But I do think that losing the red ribbon might be symbolic of the Nanoha franchise losing sight of the magical girl side of its excellent magical girl/mecha fusion.
That in turn may help to explain
this anime's success...
(Just so people know, that last sentence is tongue-in-cheek, lol)
Anyway, good points, Kaijo. I agree with you that Nanoha in the movie probably could have used a bit more fleshing out. Perhaps a few minutes more should have been given for the backstory between Nanoha and Arisa.