Demona, that first Tifa's breasts were too small, and that Cloud's sword looked like it was wrapped in toilet paper, and It was hard to tell, but I'm pretty sure his arms weren't muscular enough. That Vincent was fantastic though, even getting the red eyes down!
The population of people who are that skinny and have Tifa sized tits is not that small. I think the best cosplays are the ones that are as perfect as possible, and I'm also a bit of a nitpicker, so I often feel the need to point out when someone gets a detail wrong.
Though I have say, not having big enough breasts seems to be a problem with most Tifa cosplayers. I've even seen one whose breasts were too big.
I've always felt one should dress to one's body type, but not to one's hair or skin color. This applies to dudes cosplaying even more than women, though, because I do not need to see any more Boba Fatts or Stick Figure Akumas.
That's not to say you gotta be PERFECT, just... if you are overweight, it might not be the best idea to do a Soul Cal Cosplay. Especially not Voldo.