Yeah that could be kinda cool! Unless you're in a place where you really need to be a certain gender, like a changing room, or bathroom. And anyway, imagine someone handing you a baby and you trying to take a bite out of it. That could get messy.
The gender bender one reminds me of a character in the anime called To Love Ru darkness, in which there's a guy who when he sneezes he becomes a girl and when he's in girl form he loves the protagonist but when he's a guy he hates his guts.
"Bro give me back my fuckin muffin"