I have been using a Suunto Ambit3 for the past three years. It has GPS, altimeter, steps, mileage. After a hike I can upload the hike to an app to look at the path, elevation and speed. I would find it hard to hike without it now. I use the altimeter and mileage to figure out how far I am from trail landmarks and intersections. What I do not like is the band, it broke after 2 years, a replacement from Suunto was very expensive, but plenty of cheap ones on eBay. Suunto has just released a new smart watch with a color screen that can display your map on the phone; too early to tell how well this watch will work out.