This is one of those situations that can be looked at both positively and negatively imo.
On the one hand, cosplaying as a popular character makes it easy to get advice and tips for successfully pulling it off.
Expanding on that, (for the better or worse) you can also compare yourself to others doing that character. Like I said, that can be for better or worse. Depends.
On the other hand, if you cosplay as a character that is less popular you run the risk of people not knowing who you are. That is both good and bad.
Anyways, myself personally, I am in that unsure gray zone.
I'm going to push my luck and attempt Kongou from Kantai Collection. (I say "push my luck" because I'm male)
Kantai Collection is popular and all with Kongou being one of the main girls people talk about so i run the risk of meeting lots of "her".
On the flip side of that, there is only one other person cosplaying as her that I am aware of so it could go either way.
ULTIMATELY,
I think its just cool to know that I chose a character that others like as much as I do.
Wow long post....