Yes it is a joke …
I was gifted an EM7455 and thought “cool, it supports simultaneous use of GPS, Glonass, Galileo and Beidou” and would have been perfect for my project. But of course, GNNS is totally broken as well. Positioning tracking works fine to a certain degree but the output of used satellites on the NMEA interfaces is FREAKING broken. Documented AT commands aren’t implemented or printing wrong data.
Now as a last ressort there would be the SDK. But its amazing documentation is full of mistakes and copy and paste errors … Not to mention it requires the unstable GobiNet driver … Unplugging the modem = Kernel panic or “stuck” driver.
Sierra + Quality Assurance = Biggest joke ever.