Hmm, looks like your Garmin has somewhere between 30h (with everything turned on) to 11d of battery life, which is not bad for needing to power a bright screen. I wear a Skagen Jorn hybrid, which has physical hands over a round e-ink display, which lasts ~3w on a charge for me. I also like e-ink better in daylight, AMOLED has gotten pretty good, but it's still harder to read in bright conditions (though obviously easier in dark ones!)