I would say
- Overall % of students who match. Sometimes people lump match and soap together. I would try to get them separate. Also how many of those are pre-lim only positions.
- Are all specialties represented over the past 3-5 years? Especially the one(s) you are interested in.
- Are people getting into some big name programs?
I think you'll find with a few exceptions, if you excel at a medical school, you can match in whatever specialty and program you want. It's important to select a program that you will excel at.