"If you are going to be really roughing it you might want to leave the phone behind and just get a nice stand alone unit."

I guess I'm wondering why - is there a difference in quality of output? By doing a comparison - I'd have a better setup by adding a GPS and software than getting a quality stand alone unit for the same price. I hardly ever REALLY rough it, I've gone at most 16 miles in a day - and then my major concern was that I got badly lost and almost lost daylight altogether. So a GPS tethered to my phone would help me have more successful hikes.

Thanks a lot for the suggestions guys! It looks like I have 2 good options so far.