I've had one for about 3 years. I use it with both Verizon and AT&T hotspots and phones. My experience has been mixed:
In metropolitan areas, it usually increases signal strength but has minimal to no impact on data speed - and in many cases it has REDUCED speed. I suspect this is due to network congestion and the MIMO operation of modern hotspots.
In rural/remote areas, I have seen some good improvement in both signal and speed. It boosted a practically unusable signal to an acceptable level. As the carriers increase coverage, these situations are far less frequent today than several years ago.
If you're in a place with no signal at all, it won't help.
All in all, I would get one again since I need the connectivity for business. It's definitely nice to have on the few occasions when I needed it.
