Before retirement I was a user on the MetroSafe system and had a hand in the planning. For the Louisville/Jefferson County area it significantly improved coverage - and we had a pretty decent system as it was. Interoperability and narrowbanding were the drivers for us.
We spent a lot of time testing, checking, re-testing and general "playing around" with the radio system before it went "live". There was one area of the county that had "dead spots" and a new site was built to cover that. However we did not have any of the horror stories of bad audio, etc. early digital users experienced.
For Bullitt County, quite frankly, "it's about time". They got a horrible radio system with way too many dead spots. They have used up all the rubber bands and bubble gum they can find just to keep what they have sort of functioning. First responders face enough risks as it is and should not be forced to rely on less than the best communications equipment available.
All I ask is just don't go nuts with encryption. Some things should be but not everything. One of the biggest gripes I heard from the public back during the big train derailment was they didn't know what was going on. With scanner apps and feeds, they would have that ability and not rely on media briefings.