My step 1 was above average, and step 2 was even better - and I didn't get an interview at Boston. Didn't apply to CHOP. Part of it may be geographical - I don't know this for sure, but I am told they favor East Coasters or those from "highly selective" med schools, whatever that means. Also, I didn't really give them any reason to select me for an interview - no ties to Boston, no connections with faculty, etc. But, I did meet a few people on the interview trail who did rotations at Boston Children's, and some even got letters from those they rotated with, and STILL didn't get an interview! So, don't feel too bad!