The San Diego RCS law enforcement talkgroups are all digital and have been for years. For the most part it works well. I hear officers yelling in their mics during foot pursuits and other high risk situations often. And I've heard sirens wailing in behind voices as well without the digitization problem you speak of. Perhaps your system needs tweaking somehow.Digital craps out as soon as someone raises their voice. Digital has not got the bandwidth to withstand an excitable police officer or firefighter calling for help...instead what you get is "digitizing." You can hear that sometimes when Ct. SP transmits with their sirens in the background...the sirens make the signal "digitize."
Someone said elsewhere to give digital and the 700/800 plus frequencies to business and non PS. I agree. If it ain't broke, don't fix it.