I don't consider myself at all proficient at the Amphilophus, but as a general rule, the more torpedo shape/flat profiles in almost any cichlid are usually feminine.
Here are a few examples, and as you can see, steepness is relative
sajica female

sajica male

festae male

festae female


above trimac male, below female


Nosferatu pantostictus male above, female below

Here are a few examples, and as you can see, steepness is relative
sajica female

sajica male

festae male

festae female


above trimac male, below female


Nosferatu pantostictus male above, female below

By the way Duanes, what's your guess on the Midas? You seem to be a fish sexing guru of sorts, at least not afraid to throw out an educated guess. I have them separated in the same tank now, basically because I'm worried they both might be female and they might tear each other up. Not that it couldn't happen with a male/female pair, but I've always had a more difficult time keeping two of the same sex fish when they are about the same size. I could care less if it's male or female, it's just curiosity always gets the best of me when they are this small.