SOLO or Stonehearth Open Learning Opportunities, based out of Conway, New Hampshire, is the east-coast alternative to the NOLS affiliated Wilderness Medical Institute. Having completed wilderness first aid (WFA), wilderness first responder (WFR), and wilderness emergency medical technician (WEMT) courses through SOLO, I have no reservations giving them a 5 of 5 rating. The programs are rock-solid.
All of my experiences with SOLO involved instructors with years of practical experience in SAR and EMS. They knew what they were talking about and were very capable at passing along the lessons. The facility in North Conway was also pretty darn cool.
I understand that WMI and AERIE also deliver top-notch training, but my only experience is with SOLO. As an active wilderness professional, I consider their training invaluable.