Only time battery dips below 60% on my AW Sport is when I've had the pulse meter running for two hours plus when taking a really long walk. Often if I don't use the training app that day, battery is at or near 75%.
That said, I've turned off background activity for most apps, as I found something eating serious battery when wOS3 first came out, and curbing background update for all but the core stuff I actually use fixed it. I didn't bother re-activating it all again when 3.1 came out as there was no appreciable gain for me letting them background update.
I suppose in the interest of science I should just enable everything again and see if battery life remains good. I just can't be bothered though! *shrug*