I went through Philly last Friday, June 30th, for the first time (but not from SXM). I have gone through customs and immigration in the past in Charlotte, Miami, Atlanta, and San Juan. I had a tight connection (1 1/2 hours) with an incoming flight from Barcelona that was an hour late. I breezed through immigration, customs, luggage re-check and security and ran to the gate for the next flight. It may have been pure luck, but I've never had such a quick process re-entering the US.