With large statewide systems, the 64-talkgroup limit is a big issue. If you're traveling across the state, it's easy to max that out if you want to monitor county-level stuff on the way, especially if you're not familiar with which specific talkgroup(s) will be of interest. Worse, the PPS dumps all talkgroups from all systems into a single list, so picking the correct talkgroups from multiple systems is pointlessly unwieldy. Having WV-SIRN, VA-STARS, and MD-FIRST, each of which have hundreds of talkgroups, all in the same profile is sheer madness to try to program anything useful.
And manually switching zones and knob positions while driving is not very user-friendly or safe.