It looks like they've gone from conventional to a simulcast trunked system.
Benefits are:
You can talk from one end of the county to another portable to portable even if hitting different towers.
If you need to add a talkgroup it takes minutes and you don't have to buy any equipment or frequencies.
If a transmitter fails, it comes out of the rotation, no user intervention.
If a site/tower fails, the rest should continue to work, no user intervention.
Confirmation/Error tone when transmitting tells you if you're hitting a repeater or not.
You can consolidate the 50ish repeaters in the county onto a 12 channel trunked system.
If a new group (ex public works) wanted wide area coverage they only need to buy radios and don't have to buy frequencies or infrastructure.
Disadvantages are.
Subscriber units (radios) cost more (but coming down in price).
System may cost more up front but over time may be cheaper than maintaining all of the existing repeaters throughout the county.
Repeater based system means if you can't hit the repeater, no one hears you.
If the system completely fails you have to switch to a conventional channel to talk radio to radio.
Currently no phase 2 trunking pagers, requires patching to a conventional transmitter for paging.