Okay, I love my GPS, but I can't make the weight of the batteries and unit worth the use. You ever try to track your path for 7-10 days? My unit will show me real time where I'm at, on the topo map etc. But at a cost... like a color screen that eats batteries, and all so I can look at this track when I get home on my computer! (using a Triton 400 with NatGeo Topo) I also find the smaller screen very limiting with regards to seeing the overview of the surrounding area. I can scroll, but on a 2" screen, seems kinda pointless!
I've climbed all over, and its always been my altimeter on my watch, and the maps that were ultimatley the final word. The altimeter works even when you cant see the peak or feature. It can be a life saver knowing what contour line on the map you are at!
As an aside, who has done a long hike with their GPS, and what was the total weight involved for the trip? I did get a GPS download from Bob and his 10+ day trip in the winds... wondered what was his "total weight cost"?