I have been trying to decide if I want to spend $80 or so on an altimeter for my backpack hunt in ID 20a this fall. How many of you use an altimeter while hunting? Is it a big advantage? I had considered buying a GPS with a built in altimeter, but I still have trouble justifying the weight of a GPS when I am very comfortable using a compass & maps. I can see some benefit to knowing your precise elevation, but how helpful have you found it to be?