Don't get too caught up on USMLE scores if you're simply trying to pick a medical school. Don't get me wrong--the scores are important--but there's a lot more to medical school than that exam, which was designed to see if you have the basic level of fundamental knowledge you need to be able to clinical years. It is NOT supposed to be like an MCAT.
Some schools teach directly to the board exams, using board review books, etc. Others, like mine, don't--and they make an explicit point of saying this. One of our deans is famous for slamming his fist down and saying "Cornell does NOT teach to the boards." He's right--they don't. As a result, I don't think Cornell has stellar board scores, but we all seem to make it into good residencies. Speaking as one who is taking Step 1 next week, the only things we miss out on are some of the random informational "factoids" that appear on the test. All of the really important physiology and pathology, anatomy, etc., are covered very well.
So I'd take board score information with a grain of salt. It's definitely not the litmus test of what your future medical education will be like. 🙂
good luck...