If Cassie Suthorn is the cringe (which I often hear) she's no different from the archetypal heroes of many award-winning books and blockbuster films.
That is not an argument for quality. :P
But yeah, even though I clearly remember that Miss I-kill-BattleMechs-with-Knives did annoy me, I don't think that, in retrospective, this character was the main problem either. As I said, it's just as likely that at that point, my tastes had simply developed to a point where I no longer enjoyed reading that kind of book.
The Japanese-style world building was not particularly interesting to me at that point. What I remember from the novels was pervasive hokiness and "badass moments" which just seemed like the plot being full of itself, if that makes sense. Plus some vague memories of really terrible writing which I'm not going to go into detail about.
On the plus side, in contrast to say, the Warrior and Blood of Kerensky trilogies, I don't recall misogynist, social Darwinist or "yellow peril" undercurrents, nor idiot plots that didn't make any ****** sense, nor a complete lack of sense of space that basically threw the established BTU out of the window, nor incredibly repetitive descriptions (good old Blood of Kerensky drinking game: Take a shot every time a characters hands are "knotted" or curled or balled into fists "in frustration").