Clinical evals, which are of course even more subjective, carry the most percentage points here (at least that's what they tell us). But to get Honors vs. High Pass you need to make minimum score cut-offs on the exam.
Here's my 3rd year strategy: I basically studied for each exam as if to Honor it (and I did, except Surgery I don't know b/c I just took it end of June). Then my clinical evals determined if I got Honors vs HP.
And yes, honoring OB/GYN was a cinch. Like I said the essay exam=joke. We were told only to give our clinical eval cards to the faculty/residents of our choosing, so I would plan ahead who to impress the most on each service. I hated that rotation, avoided doing real work (and most residents), yet somehow I got Honors
What I learned about in-house exams is they don't always cover what's in the shelf-exam-type review books. It's more based on faculty's preferred learning objectives, so if they give you a syllabus or specific topics, then focus mainly on those. I remember our Family Med in-house exam came DIRECTLY from a stack of articles we had to read and memorize factoids from. No outside reading was required. Talk to senior students in your class about the in-house exams.