Okay so didn't find any LTE at Northlake mall area, but I did expand a little on the sensorly map around the I-77 & I-85 interchange. On the way there my phone was in eHRPD mode and made the transition to LTE flawlessly, but on the way back the phone was in Evdo Rev A mode and it took an airplane mode toggle to get it to pick up LTE again.
Gratuitous speed test screen capture: