A lot of generalizations. Hopefully nobody gets offended by these.
1) The time required to get ready. My good friend spends an hour doing her hair everyday, plus makeup and such and she's at almost TWO HOURS PER DAY. The social requirements for how women are expected to look are absurd. I foresee makeup going out of style in the coming generations and natural beauty prevailing. I hope at least.
2) As a 6'2" tall male, I'm often on the edge walking home at night. I couldn't imagine being a girl, walking past a group of men. I'd be intimidated.
3) On the same token, even with martial arts training etc., I wouldn't like knowing that a lot of people are bigger/stronger than I am. Presumably it's something you get used to, but it'd just be a weird feeling. It's almost a necessity to take some sort of fight training to have a tool in your pocket, worst case scenario.
4) Again on the same thread, I would hate knowing that men have an advantage to me for sports. For instance, I just started road cycling this year. Within two months, I was riding with the highest group with a 35+KM/H average speed. There is only one woman in this group, and she's been cycling for 25+ years.
5) Periods, and the related mood swings. Actually, mood swings in general. From what I've seen, women bring too much emotion into a thought process. Many women can't think rationally, because they incorporate too much emotion into everything. Arguments are the biggest example I can think of. It will start as a calm conversation, then if my girlfriend feels I have the upper hand, she'll use her tone and dialect. I have never understood this.
6) Being labeled a slut for sleeping around. A slut could be both male or female in my eyes, however not to society. If a girl/boy practices safe sex, with clean people, there is no reason why sex can't be enjoyed frequently by both males and females.
7) Female executives are still not entirely accepted by society, for whatever reason males are still being promoted more than females. The executive list of the fortune 500 is proof. This situation is improving though.
8) Maternity leave would suck. Having to stop working for a year or so to recover/raise a child.
9) That akwardness that many males portray around an attractive female. It limits a lot of good conversation etc. Too many males incorporate sexual jokes around females or flirt constantly, I'd be fucking annoyed by that.
I'd better stop now, I've got shit to do today.