I worked for them for over 5 years. They started out as Eagle Air Med, then changed to AMRG, then changed to Guardian Flight. They were bought out by a big corporation called AMGH. The CEO for Guardian Flight (not very good at his job and was fired shortly after AMGH bought them) hired a couple 'goon' friends of his to be the DO and CP. When I left this past year, those two were still around. No one likes either of them (pilots and medical crews alike). If you turn down a flight or put a flight on hold because of weather, they will start blowing up your phone and second guessing your decision. I put a flight on hold for severe turbulence, and was immediately called and berated for doing so.
My advice? Stay far away. But, if you're looking to make a few bucks out on the Navajo Indian Reservation in the desert southwest, go for it. You'll work a 14/14 schedule (first 7 are day shift, second 7 are night shift). You'll fly 2 flights per shift, and you'll work 10-15 hours every shift. Lot's of guys get burned out after 6 months and end up leaving. High turnover. But, the medical crews are pretty awesome, and the maintenance guys do all they can to help you out.