I don't think
Anna is boring, but I do think it's definitely popular enough to be off-putting. I wouldn't pronounce
Anna and
Ana the same way, so I don't really see them as interchangeable spellings like Katherine/Kathryn or something like that. I know 2
Annas and 1
Ana (but I think her name is actually short for something else).
I prefer
Anna, probably just because that's the form I'm more familiar with, and it fits with the type of names I generally like.
Ana Mae reminds me of anaemia for some reason...