I haven't found the battery life to be an issue. Part of that is how quick the Apple Watch is to charge. I throw it on the charger when I wake up, and it's charged by the time I get out of the shower.
I like wearing my watch at night for sleep tracking, and the longer it's on my wrist, the more data it's capturing, which my hope is that in the years to come, can be harnessed for improving my health, somehow.