Kuune, what strikes me about all the wildly varying feedback is that you may not have a PS that really "flows" well or tells a coherent story. If you're jumping around a lot, this might account for the wide variety of responses. Or maybe you just have a lot of different personalities looking at your essay, and each one is reading it uniquely.
I'm in the throes of this myself (hi, aerospace!) and it's been very enlightening for me. So far most of my feedback has been consistent, which reinforces my belief that certain parts of my essay are solid and the ones I don't feel solid about are showing up on everyone's radar as a bit troublesome.
Here's my basic strategy thus far:
1. I've collected a wide variety of readers, both people who know me well, and people who don't, and including people both familiar and unfamiliar with the medschool application process. The only common unifying theme is that everyone I've picked is nitpicky and good with writing.
2. If two or more people have made the same negative comment, whether in general or about a specific sentence/phrase, then it clearly needs work.
3. If only one reader has an issue with a specific thing, I try to consider the source. Perhaps it's just hitting a hot button of theirs, or perhaps they have a certain understanding or bias that makes them feel this way. For example, a friend of mine who went to law school thought that my PS was way too personal and intimate, because it would be way too personal/intimate for law school or grad school.
4. I'm finding all comments very enlightening. I don't have to agree with them, or incorporate them, but if someone had a certain response based on what I wrote it's important for me to consider that an AdCom member may read my essay the same way.
Hope this helps! 🙂