Regional One, based in Spartanburg, is quite busy also. They cover quite a few counties surrounding Spartanburg, including several up into NC. Their base is about 1/4-mile from my office, so I hear them lift off anytime I'm in the office. I'd say on average I hear them lift off twice a day, sometime more.
BTW, Regional One is "owned" by MedTrans also. MedTrans is contracted by SRMC to provide air ambulance service.