One of our test setups ran through 117GB in July on a Visible SIM card (but not on a CAT18 device).
The 5 Mbps limit seems to be a thing of the past. Aside from the effect of running at a lower priority than Verizon SIM cards on Verizon’s network when the network is congested the experience has been that the Visible connections run a t the same speed as Verizon’s, possibly with a somewhat higher latency.
Of course: YMMV.
Cheers,
Z