said by the4Gguy:
I'm actually having less success than you are. We operate our own 4G network (just in the turnup phase with 2 sites at this time) in the 700 block so I've just purchased an AT&T model. Unfortunately I can't even get the unit to connect, let alone get to the LTE toggle switch. Ironically, if I go to the "Carrier" preferences pane and turn off automatic, our MCC-MNC shows up next to AT&T and T-mobile, so I know the radio is at least scanning and can see our network however the iPad just says "Searching..." and then finally goes to "No Carrier". I'm definitely going to be watching this thread and will reply if we have any luck moving forward...
what bands of LTE are you operating on? VZ is on one side of the 700 and ATT is on the other I believe.