Let me start this off by saying I am probably not the most qualified to speak on this... so I am going to go ahead and speak on this.
I mainly use GPS for hiking and trip planning. I spent a fair bit of time looking into the best option for a handheld GPS/NAV unit that had everything I desired. After weighing all of my options I actually went with an app for my phone. The reasons were simple. I already owned it, it is a pretty high end piece of tech, it's GPS capabilities are pretty comparable with modern stand alone GPS, and if using for GPS alone the battery drain is really low.
While the phone screen is pretty small, one account lets you long in on any device. iPad, computer, laptop, phone. So if you're running a tablet mount in your X then you will have a decent size screen and decent location services.
The app I use is Gaia GPS. They have a premium service for about $40/year, less if you buy a 5 year plan. I know I know, subscription plans suck, and they used to sell the app for $20 with lifetime, but I think the sub helps them continue to update and add new layers and sat images. This will come with all the nat geo maps, all their satellite overlays, topo maps, as well as a bunch of overlays for hunting, public/private lands, and they are really starting to get into the off road nav aspects of it. I have tracked and planned hundreds of miles of hiking thorough this app and have been pretty impressed with it. I will say that it is more geared for hiking, but the overlays should serve you well.
To sum it all up, if you already own a capable device, using its existing GPS/NAV features with a powerful app like GAIA GPS might be a good bet.
hope this aimless rant helped a bit more than it hurt
![Wink ;)](https://www.sccxterra.com/smf/Smileys/akyhne/wink.gif)
LINK to their site
https://www.gaiagps.com/premium/ALSO,
This seems like there will be loads of helpful stuff in it, but I DID NOT read it!
https://www.overlandbound.com/forums/threads/ask-me-about-gaia-gps.6959/ -CVX