So follow up:
I got the boards and flashed them to run the firmware. It was super easy to get them up and running, and pass encrypted coms between my phone and tablet.
Step 2: I mounted them in little Plano boxes with a USB battery pack and started moving them apart. With the craptastic antenna that comes with the board (~3 SWR at the frequency range I'm using) and .21 W transmit power I put one radio on the top of a truck at work (~15 ft high) and the other on the dashboard of my car and drove away. This was in Tampa proper so multi story buildings. I got 0.3-0.4 miles away before I lost the ability to send messages, and the node dropped completely by 0.45 miles. I'm thinking I could get a solid 1-1.5 miles with just good antennas and maybe mounting to the roof of my car. Obviously less urban areas would help LOS.
Now I'm seeing how long the boards run on my little 5000mAh battery packs. and we'll go from there.
Off the top of my head: this would be awesome for a group of folks living and operating in a small to medium town. You could pretty easily set up a mesh that covered quite a bit of a city with "base" nodes on houses or other high points, and "travel" nodes with each person checking in with the "base" nodes as they travel. An ad-hoc private cell network. If you care to be all tactical you can run
ATAK encrypted over this network, or just have a storm/power outage/mutual support group commo network.
The other thing I'm going to experiment with is putting one of these in my bag, one in the wife's bag, and a GPS enabled one on the dogs when camping. If a dog runs off after a creature or whatever, being able to ping their GPS anywhere within a mile or two and plot them on a map regardless of cell coverage or Commercial "Dog GPS Tracker" plans seems handy to me.
The whole thing is low power enough that you can build a node with a couple 18650 rechargables, and a 15W solar panel and it'll run indefinitely. So remote/low maintenance nodes are a pretty easy thing.