The idea of a baseball-themed manga is definitely not that original, but the manga makes up for it with very interesting characters that you either love or hate (the main character took some getting used to). It is shounen so it has a bit of fan-service for guys.
I enjoyed the slap-stick, cross-dressing, and nonsensical humour. If you don't like extremely random, violent, and insane utterances or acts ( a TON of it), this manga is most certainly not for you.
Actually, Mr. Fullswing would be a lot more serious if not for the main character.