It is different, from a social and legal perspective.
Few 16 year old girls have had the experience of having their entire life revolve around the opposite gender during their formative years. Most 16 year old boys have. This makes 16 year old boys more vulnerable to the whims and caprices of older women. Because they have been trained to obey them and regard them as the alpha and omega of existance.
Legally 16 year old girls have recourse over their older partners. They can threaten them with charges of rape(charges which will actually be believed), can legally compell them to pay child support or alimony.
Socially 16 year old girls have more of a support system then 16 year old boys in a relationship with an opposite-sex adult. She will be seen as the victim and he the aggressor. In the reverse it's often believed that the younger boy is the agressor and sometimes, the elder woman the victim. This ambigious situation results in more social support for a young woman in a January-December relationship then support for a young man.
Physically and psychologically a 16 year old girl is more mature then a 16 year old boy. By 16 she is probably at the tail end of her adult development. He isn't until he's in his early twenties.
It would be identical if the 16 year old girl took on all the risks of getting pregnant, couldn't have an abortion or give the child out for adoption, was seen as the agressor who got "lucky", was delayed developmentally, would get little help getting out of the relationship if she needed it because it was "her bed, lie in it" and few people recognized it as an abuse of power on the part of the man.
My personal opinion is that the age of consent laws are rediculous. If anyone who has started puberty gets into a relationship with a vastly older person, they should replace all the age of consent laws with something like this... the younger person can, whenever they want, "divorce" the elder person, recieve all their assets and the elder goes to jail for 5 years. No pass go, straight to jail. No freebies for the ladies.
It's draconian, and it puts a lot of power in the younger member's hands. Hopefully it would teach stupid fuckers who get in relationships with teenagers that putting yourself at the mercy of someone whose emotional development is minimal is not a good idea.