I keep calipers at every machine, and we mostly use digital Mitutoyo for the ease of use. 6" and 12". I have dial calipers all over the shop though. Always something being measured quick.
I leave the Mitutoyo calipers on 100% of the time. The only thing the power switch turns off is the LCD, the absolute measuring head is always on. The LCD uses so little power its negligible. I have only had to replace batteries maybe once in the 3+ years i've had the 6" caliper. Have yet to replace the battery in one 6", or the 12".
Calipers are only trusted to +/- .005", but they're so much faster than a mic that we use them almost like a tape measure. Important measurements get taken with a mic, bore gage, indicator, etc.