Yea, we still have internal rankings in thirds. It's actually a little different than that though. You can take a look at the student handbook for specific details but the gist of it is we're ranked internally into Top 10, Top 10%, and then Top/Middle/Bottom third. At the end of preclinical years the top 25% of the class (based on preclinical Block Exam and Clinical Skills Exams grades (not quizzes)) is eligible for AOA, and then when you apply for residency your preclinical grades and your clinical grades are averaged and the rank of Top 10, top 10%, or top/middle/bottom third is reported on your MSPE (medical school performance evaluation) letter. There are some other things that are actually just true P/F though (SI, humanities classes/electives, etc.)
I talked about this before in this thread but I have mixed feelings about it. On one hand, having internal rankings kind of sucks because it still feels like you're competing with your classmates and adds a layer of stress to things. On the other hand, I've read in a lot of places that having rankings is actually a good thing in pretty much every school outside of the Top 20 because it gives students a way to differentiate themselves. I personally wish we didn't have rankings though.
It's not something that openly causes feelings of competitiveness amongst the students though. My entire class is super collaborative and the issue of rankings almost never comes up. It's just something that's kind of there in the back of our minds whenever we take a block exam. Being in the Top 10 will definitely help you come time for residency apps, but I feel that unless you're in the Top 10 or in the bottom third it's not something that will really change the outcome of your residency application significantly. There are rumors that preclinical grades in all schools may become more important now that Step is P/F but the truth is we don't really know.
Tl;dr - yeah it's kind of unfortunate that there's internal rankings in my opinion but there are pros/cons to having it.