I am visiting here on business and I think the MOT II systems here are hard to lock on to when compared to elsewhere in the country.
What I read seems to indicate that TRS Systems are good for deep penetration (into buildings and structures) over a smaller area (1 - 8 miles) while conventional/repeater systems have larger coverage. I think that Phoenix, for the most part, doesn't need a TRS when compared to a place like Chicago.
I've been basically up and down on 17 from Dunlap to the 101, in the city. While on Dunlap I just barely get the White Mountain station; can't get Phoenix downtown, and if I go one block north of 101 the White Mountain CCs go away.
The other challenge is calling other agencies if they can't hook onto the TRS. Back home, in San Antonio, TX; the city PD and SO are on EDACS/ProVoice/ESK while outlying areas are either on conventional and Analog TRS's. It can be a real cattleplop when agencies try to interoperate without everyone carrying more radios and MDTs. Not unusual for Dry Gulch EMS to arrive and have to arm wrestle with SA EMS because both get dispatched.
I've also seen where TRS have conventional crosspatches for mobiles.
Whatever it will be, I hope it's as active as AZ DPS.