My phone is an iphone 5. To Burton, most US contracts include free roaming at least in the US, so that's not an issue.

I've used Schmidt SON generator hubs and I don't like them on tour, because you get nothing (or sometimes less) on those long uphills. I have two good batteries I'll take (one 8000 mAh, the other 10000) to charge my phone and ipad mini (and maybe kindle). Ironically, this tour is southern east coast, so it'll be flat and would have been ideal for the generator hub.

The iphone does everything I need. I use MotionX to track my route. I also have the entire planned (ACA) route loaded, the 120 ACA-mentioned campgrounds loaded as waypoints, and I've cached about 2.5 GB of tileset data so I won't have to exhaust my monthly data allowance.

MotionX will even do exactly what I want: send an email w/ GPS fix each hour. The problem is that either the GPS is on that whole hour, or the emails are only sent when the phone is unlocked and the app is in the foreground.

Except for the battery issue I see no reason to have a dedicated unit. Instead, I use at least as much space/weight for the batteries :-). W/ the two batteries I'm taking I should have to plug in more than every three or four days, minimum, even if the phone is on all the time. State parks, and sadly a few RV parks, so plenty of power.