They tout progressive protocols, which are average at best. They run their personnel into the ground. They hire medics and now force them to work as basics (not an issue if you're a basic, but a slap in the face if you're a medic). They've been slammed on multiple audits in recent years from issues ranging from collections, logistics, burnout, and general sustainability.
My former partner was an ATC medic. I should get her on here to rant about the shortcomings from an interior perspective. Another coworker worked for ATC, was hired with a group of 20 in 2006- there is now only one medic left from that hiring class. They had been hiring nearly 40/yr at one point (not sure what they're at now), but they're not near big enough for that to be replacement of retirees (I'd be willing to bet that retirees make up an exceptionally small portion of that number). Retention alone, or lack thereof, should tell you all you need to know. If you can't keep employees, despite paying them fairly well and considerably above average, there's something wrong.
If you want to be a paramedic, you would be much better off going a couple miles north and working for Williamson Co.