About GPS... When I know I'll need it, I put my phone on a magnetic dash mount and I'm en route. When not using GPS, the phone lives in my front pants pocket.
Yesterday, I was out driving and on a whim wanted to go to a Best Buy in an unfamiliar area. It's both awkward and obvious if I try to remove the phone while driving, so I told Siri 'Take me to Best Buy.' She gave me some options and the first one was what I wanted. Press 'Start' and go. The Watch gave me taps and directions.
It dawned on me that because I was wearing my S2, this could have taken place had my phone been left behind. So while I've yet to rely on solely on Watch GPS, I know have a greater appreciation for having it.