I'm generally not a fan of characters going through major sexual augmentation, and would simply prefer that a new character be made so I have some interesting content to go along with the sex. And we already have a large variety of characters to choose from. And even if you just want a couple new sex scenes, why give a random female a dick when other herms already in the game could use new scenes or even full-on expansions? And don't even get me started on genderbending...
Unless it's an active goal the character is pursuing, I'll always argue against making a character variant. It does make things more complicated, especially when the champion can already come in an increasing variety of appearances.