I had the 2018 390 Duke which comes standard with MyRide.
The 790 add-on doesn't include maps, only the phone and music function. Maps only works on the 1290 duke.
IMO it's a waste of money. The only thing i noticed having my phone and helmet comms connected is your contacts come up on the screen when someone calls and you can see what music track you're playing and select tracks with the LH controls.
Nothing Siri or Alexa can't already do so i don't miss it at all.
Hope this helps.