I used to use an eTrex mounted on my handlebar for moto trips, and occasionally I hike with it, but honestly, since I got the “Topo” app (for .99¢) for my iPhone, I don’t bother carrying a GPS much anymore.
You need to have wifi/cell service to download the maps (which is really easy and fast to do), but once you do that, you can use it basically anywhere, since location tracking isn’t cell service-dependent. it allows for waypoints, etc, as well. For as much as I need a GPS (which isn’t much at all) it works great. One less thing to carry, as well.
update: coincidentally, I just got a notification from Seek Outside about a new blog post with tips on using smartphones for nav: