If I were to carry a smartphone for this purpose then I would get a worse experience than I do on a larger screen, and it would hinder my ability to use telephony services when I need them.
For my needs, those services do not belong in one device.
For comparison, I occasionally don't charge my phone for two weeks.
Edit: apologies for editing :)
I wouldn't really know, because never have I been in a situation where I actually used my phone nonstop for 9 hours. =]
For my typical usage, the battery will last several days at least and probably a bit more if I put more effort into reducing battery consumption. I actually don't know how long it'll last since it's never died. Definitely not two weeks, but long enough for me to not really worry about the battery life.
All that said, I can definitely see the appeal of a phone that lasts two weeks. I think the Note 3 sits at a decent compromise between that and my old phone, a Galaxy S3, which could barely last 8 hours (of typical, very intermittent usage).
Battery life trumps navigation, for me, comfortably. If I'm lost after a long day, I need the option to phone my destination.