I purchased the SpotX tracker recently for my daughters to use while hiking the Pacific Crest Trail. They are on the trail right now and the tracker is set to send a position once an hour. We are lucky if there is 1 or 2 tracking points a day. Texting seems to work, although it had a few problems there. Overall I would say as a tracker, it fails. For texts from the back country it seems to be ok. If needed, I hope the SOS button is going to work. On the other hand I had the Spot gen3 last year. It tracked ok on a 50 mile Mt Whitney hike. It even tracked on a flight in the Cessna from CA to ID. Very disappointed in the SpotX, will probably return it. The required year long subscription will be a loss.
I assume that performance wasn't simply caused by the position of the device?
The tracking of my InReach is rock solid.