Good Wolf said:
First off, what would you choose.
Well a person could have a lot of fun\good doing both.
With invisibility a person could stop a lot of crimes from ever happening, but also with that would come huge temptations like you wrote. Could a guy just peek in the girl's shower room once, and get his fill and spend the rest of his life fighting crime and doing good.
For me it would be do I have the guts to choose invisibility over flying, because it would mean no sneaking around doing things for personal gain at the cost of others, nor indulging in activities of lurking in on innocent people.