Perhaps it has been discussed before, but I'm still confused as to what makes a model underrated or underused. With musicians, I get it. Their album or concert sales are shabby, and they don't get the fame they deserve. Also with athletes whose talent isn't acknowledged no matter their results, or actresses who lose out to many roles.
But the way I see it, the standards of measuring a model's success are not as easy to define. First of all, you have to take in the model's age, other pursuits (i.e. school) and her career objectives, as well as her agency's. Not all models are eager to work internationally constantly, do tons of runway and editorials. Some opt to do sporadic work, some prefer commercial work to high fashion etc. So it may be in large part about personal choice.
Secondly, how can we rate a model's success if she's only been active for a couple of seasons, or conversely, if she's been working for many years? Is it a matter of visibility? Plus, until recently with certain blogs and forums such as TFS, there weren't really any public "reviews" of models, that allowed us to see how casting directors, editors, and designers assessed them.
Having said all that, I do think some models are obviously underrated, in correspondence to their (seeming) career objectives and beauty/talent. Marina Perez comes to mind.