I use mine without a phone. There's a Windows application you can download to do the syncing.
Main uses for me are bicycling and sleep tracking. Having the GPS on really burns through the battery...I could probably get about 2-3 hours usage on a full charge. Without GPS it lasts 2-3 days.
My only complaint is that the area around the screen scratches extremely easily. I've had mine for about 3 months and it looks like I've been rubbing it in sandpaper.