I get a nearly identical charge profile to the one OP described for his 3 on my six: I charge before bed, and if I skip a charge one night, I still have battery (in the red of course) when I wake up.

Offer not valid if I do an hour of exercise during the day, or game heavily (I've been known to zone out on 2048 pretty hardcore), but for normal use, sure.

Apple Watch isn't trying to be anything other than a charge-daily device, it's honestly kind of incredible that something that small can be a full-fledged cell phone and still last a full day.