I'm less concerned with realtime nav than basic computer functions, with cadence, heart rate and tracking for Strava. That's how I generally keep up with my weekly miles, and get an overall idea of how much I've improved from month to month. I also find HR/time to be a much better indicator of calories burned than any guesswork from other metrics. That said, next turn distance would be handy as both a motivator ("I can do this for one more mile and then I'll rest at the turnoff") and in case I need to take a very convoluted route.

I'd like to see 12+ hours of active battery life, to be able to do two 6 hour days between charges. Some leeway in that is handy, as ideal (so I want to keep riding) or terrible (so I still need to go farther to get to a good overnight spot) conditions keep me in the saddle for a while longer.

That's the problem with my Kyocera; the battery wouldn't last a full day of tracking even with very little screen use. The Lezyne and others use plain LCDs that don't eat up so much power, but none of them specify a battery life.