I first bought a Garmin Montana back in 2012 and have been using one ever since, logging around 350,000km on them.
I say them because I am now on my second, but its a good thing...so lets start with that.
In 2017 after around 5 years of use my Montana was acting a little weird, a few glitches so i call the head office in Missouri to see if maybe I was missing an update or if the unit had reached the end of its life.
Thir simple response, send it in and we'll trade it out for a new one, so customer service wise I cannot fault Garmin at all
The Montana is a very strong and durable unit, made for navigation. Personally I prefer a stand alone unit rather than using a phone for navigation. It is made for one task and made well, where a phone being used is just one of the downloaded or included apps, so not its primary function, my personal opinion, and have seen too many other riders eventually have issues with phones using as a GPS
The one in the image is my current unit since mid 2017 and has over 160,000km on it.