The two North Central Texas public safety NXDN systems are
SWRCC, covering Cedar Hill, Desoto, & Duncanville, and also
Lancaster Public Safety. These four cities are in southern Dallas County.
Highland Park is using a DMR
system. A couple of years ago, Highland Park submitted a licensing request for 700MHz frequencies, for a new trunked system. They would have been joined on this by University Park and SMU. However, I don't think the license was ever granted. They may, at some time, try it again. Or, once the Dallas/Dallas County P25 system, currently under construction, goes live, they could be invited to join it.
Many of the area school districts have either moved to DMR or NXDN, or at least updated their licensing to allow for one or both of those formats. I've noticed a couple of counties to the west of the metro area that have added NXDN to their licenses: Palo Pinto County & Comanche County. I'm down that way usually at least once a month, and so far, have not seen any activity using anything other than analog or P25 conventional. And, of course, eventually railroads will move to NXDN system-wide.
I definitely would add DMR & NXDN. ProVoice would not make a whole lot of sense, unless you spend a lot of time in the Bexar County/San Antonio area. I've read that they will move to P25, eventually, but it may be another year or two. The other ProVoice system (other than DFW Airport, which is migrating to P25) is
Abilene. Abilene will also be moving to a P25 Phase II system in the near future.