I don't think they've become too stereotyped. Certainly the whole aspect of Klingon honor and ritualistic tradition was overly mentioned, but generally it was shown as utter BS by a majority of Klingons in political or military power.
Worf is probably the truest Klingon, following the honor code and traditions of Klingon culture more devotedly than any Klingon of the Empire. He was basically uncorrupted by the true nature of Klingon politics.
Martok is probably the most realistic Klingon on the show. He can certainly see the corruption of the highest levels of Klingon government, but, as much as honor would suggest removing corrupt leaders, he stays quiet, and obeys such orders, even though it could cost the Klingon Empire needless lives and ships. He abides by some cultural traditions, but for the most part, doesn't give a damn about them anywhere near as much as Worf does. Sure, he believes in such and such tradition, but for the most part, it's lipservice, not devotion.