Well, I'm going to miss the large display the smartphone offers. But with a back up power brick for the phone, there's no reason to change. I've had no problem using one set of two ni-mh AA batteries that last me aprox 2 weeks(with two more as my back up). but with a back up "power brick" the power brick puts the weight, way over the top(at .5-1.0 lb for one bricks weight). both the phone and my GPS weigh about the same. So I'll make up for the rather small display with a pair of magnification glasses, that I already carry on the trail.