I am going to disagree somewhat with this. The Klingons of Star Trek III are still not Samurai-Biker-Vikings with no brains and an endless need to stop everything to settle honour debts.
I never said they were. I just said the movie was the first step in the process of their transformation, the first time we saw them talk about honor. TNG then picked up on that passing reference and expanded on it as part of its redefinition of the Klingons.