Iphone vs separate hotspot box

We have both AT&T and Verizon hotspots, along with Tracfone/Verizon phones with hotspot capability. The big advantage for us with our hotspots is that we can connect them to our roof mounted MIMO antennas for increased signal strength. One MIMO pair is omni-directional, while the other pair is directional using our crank up OTA batwing antenna. We've found that the directional MIMO pair often gives us a better signal than we can get with our cell amplifier/repeater. As said, one hotspot often works better than the other in various locations.