The new form is a real pain. I've tried filling it in with acrobat as well as with Preview (I'm on a Mac).
Originally, I couldn't even read it with Preview. But after having opened it with Acrobat and re-saved, I was able to use it in Preview. I could even save it. But for some unknown reason, a new save will lose everything that was in the last version. I have therefore the whole form saved, filled, but separated in 3-4 pdf...