This is a massive winning point that MRA brought home.
This last trip I did, I prepared tracks/routes for the first 7 days for the group (10 people). Packaged it all, uploaded online, everyone dowloaded/installed, and off we went.
One day where we used a different route/planning, the problem to share the specific route along the road proved hilarious.
10 people, of which most had Garmin XTs of various denominations (a few XT1s a few XT2).
XT1 and 2 cannot send data to each other via bluetooth

They use different companion apps as well.
Some people (me) don't use the companion app as it fucks up the way the device works...
Even the people with the Carpuride unit (no idea what software they were using to navigate) didn't have a clue.
As I was observing mayhem across the lunch table as they tried to figure it out... I was thinking of how MRA addressed the user problem there.