Sites at Barium Springs, Anderson Mtn., Mooresville, Huntersville, Concord are currently operational. VIPER Discussion sticky at the top of the NC forum page has details. Another site near I-85 and US 29 is due to come online soon.
As long as you have the CC and alternate CC frequencies listed in the database programmed in Motorola 800 Standard mode you should be good to go. Use the control channel only tracking feature.
Your mileage may vary depending where you are located. Everything thing at the moment favors the north except Concord and Heathway (when it is available).