I´ve been going to cons since I was.....like 15 or 16 (so yeah....9 or 10 years) and I´ve never had a problem either at the ones I´ve gone to in the US or at the ones I´ve been to in different places in Spain. It´s really a thing about having a bit of common sense, and knowing what to do (and not do). Also, I guess, some luck must be involved--sometimes you´re just plain lucky not to bump into certain people.
The most I´ve had were a few girls follow me when I was Sesshoumaru, but that was normal (hey, cosplay---I expect and thrive on at least a bit of attention, frankly. I want people to take pictures of my hard work) and a few guys spout the lamest pickup lines ever (the kind that have your looking at your friends and rolling your eyes) but that´s it. The absolute worst? Getting catcalls while cosplaying....by people who weren´t even congoers when we were on our way to a con. So I don´t count it as a "con experience". Cons aren´t bad, IMO. They´re fun!
I totally LoL´d at the female perverts thing.....because yeah, I know a few girls (one or two of them friends of mine) who are total perverts. And they enjoy making innocents like me blush with pervy comments. XD