There's only so many different ways we can write evals, and yes, every Attending is different in how they handle it. Some will give straight averages, some will get straight honors. A lot will write just a few choice words, etc. Which sometimes makes the whole thing aggravating for medical students.
Personally, I will try writing nice things that will hopefully end up on your letter. I don't take too many students, so I try to get to know you guys personally. Even when I was a resident filling these out for the attending, if we got along (I didn't have to adore you), I would try to make sure you stood out a little from the pack.
The flip side is, and I only did this ONCE. And I know a surgical resident that did this ONCE to a medical student. Both deserved it, we took the time to absolutely trash someone in their comments. They were stupid and furthermore lazy. Failing them would've been too much work to talk to the dean, etc. But our respective attendings agreed 110% with our assessments and paragraph long trash-talk and signed off on them. So not ALL MSPEs are the same 🙂
I remember one of my sub-i electives didn't write flattering things about me on the eval. Not horrible, just "needs to read up on this more," kind of thing. But I got an email from my school about it. I later matched into that residency. A year or two later he took me aside. He remembered what he wrote. Said actually the nicest thing, "I didn't think much of you when you were a student. As a resident I think you are phenomenal."