top heavy power consumptive and intensive application(s) (I would assume) would drive that average down.

properly installed kodi (used) would drain it quickly (I am sure)
proper telephony would drain it quickly (I am sure)
speaking of which...
a few things I noted were that ...the pi 3 b is on the whole considered "almost" to the point of desktop replacement...(as per statements from those who blind-ran applications in a plug and play fashion.....which says volumes unto itself...)
the only things negative I have found thus far...
is that:
some have noted the media players have issues playing film ..
some have noted that youtube playback has issues with speed of delivery without stuttering ...and tearing...

(yet again...these were the mentions from "open-box plug-and-playing" ....blind running applications ...without any kind of optimization, tweaking or testing.... to see how better run said programs.)

(So yes...
that being said...)

I would safely say that handing such devices to pretty much any of our community would most likely net a "good to go" verdict after enough testing and tweaking ...

Even with truly heavy use ...as long as it can make 3-4 hours before swapping batteries...
then that is bearable.