REI has some of the best information I’ve seen on handeld gps units. If you’e looking for one I encourage you to check out and read their article.
Should I Use a GPS or Smartphone?
While some smartphones can be used for navigation, a handheld GPS unit offers some key advantages.
- Durability: Handheld GPS units are built for backcountry use. Unlike smartphones, most are waterproof so rain or a dunk in the stream is not a problem.
- Battery life: A handheld typically runs 15 hours or more per charge. Most use readily available AA batteries and have the option of using rechargeable or Lithium batteries for longer life. With smartphones, you are limited to a wall or car charger.
- Coverage: All a GPS unit needs to accurately locate your position is a view of the sky. Most work well even in dense tree cover. GPS units are not limited by your cell phone provider’s coverage area.
- Features: Handheld GPS units are equipped with a barometer to help track changing weather conditions, an electronic compass for direction finding and an altimeter/barometer to find where you are on a vertical plane. Most units allow you to wirelessly exchange coordinates, trail routes and geocaches. You can even wirelessly connect to computers, heart rate monitors and other ANT-enabled devices.
- Mapping: GPS units don’t require a cell-phone data connection to download mapping, so mapping is always available. Many GPS units support a variety of mapping options, including topographic, road and waterway mapping, plus satellite imagery. More detailed mapping does need to be bought separately, but it is a one-time cost.
For the full article check out this link