I have switched, but have no experience yet running up against the limit. I asked more than one agent what happens when i pass 22gb of data. They tell me that I can be throttled back during busy times and in busy markets. Other that under those conditions I will not be throttled.
They also tell me that each phone has its own limit, meaning that if one reaches the 22 gb the other phones on the account will not be affected.
As I said, I have yet to experience even the first month on the system. I have three lines with one dedicated to use as a full time hotspot. I replaced a Jetpack with an old Samsung S5 because the S5 outperformed the Jetpack in speed and reception.
I had originally planned to get rid of my home IP and use this third phone in its place but the speed varies too much at my home, even with an external antenna. May have to ditch the third phone idea, altogether.