2019 Grand Touring, new in April. I was having issues with the radio sticking on a station on startup, worsened to picking a random station and sticking, worsened to defaulting to Radio Sources on startup. The nav was also sticking on starting point, distance mileage and ETA. Plus the usual interminably slow boot-up (I've also got a Forester that brings up nav/radio/phone more or less instantly). Dealer did the update from .100 to .300 and it fixed all of those issues. Boot-up is at least 1/2 the time it was before, no more sticking.
If your car is still within 3yr/36k warranty, and your dealer refused to update your firmware, just tell them you ran into all sort of glitches with it. They will do it. They can charge Mazda for the labor. Why not?
Dealers are not authorized to update firmware w/o customers explicitly complaining about it. So, do complain....
I just upgraded the OD from 70.00.100 to 70.00.352
Also upgraded Music Database from 00.08.000 to 00.09.000
It fixed my intermittent Voice Recognition issue, and XM seems to load quicker. Now if I try to use VR before it's loaded, the banner displays a "Voice Recognition Software Loading" message. It never did that before.
So not only does VR now work 100% of the time, attempting to use it before it's fully loaded doesn't kill it for that session until I restart the car and do a from-fresh load...I just get that message and then it finishes loading and it works.
edit to add: The dealer did the update. I exaggerated my issues to prevent any pushback. The service scheduler told me that they would do the update, but that Mazda continues to be in contact with XM to resolve "ongoing issues," and that the update might not fix the issues I was having. This was on March 10.