They had a EF Johnson Multinet system that was upgraded for rebanding with new subscriber units and infrastructure. They then upgraded the system to P25 with firmware flash on the subscriber units and new infrastructure. To replace the entire system would have cost millions more.
It would have been best to use the new system for non mission critical traffic first (DPW, schools, parks, etc) to work the bugs out. After the system was working properly, then move PD & FD over. Since the system was using the same frequencies as the old system, it would have been difficult to have both systems fully available. (the Multinet ability is still in the radios I believe).
Supposedly some of the issue is with the updated radios not working as well as new ones. I have not heard of any further updates since this first was reported several weeks ago.
chris