We have had Verizon forever. I can't really answer your question about pros and cons of using your I-phone as a hotspot. We both have 5's and have used them for short durations as hotspots, but generally have the MiFi on.
The benefit of the MiFi for us is that we haven't really found anyplace so far that we could not get a signal. In addition, the newer/smaller printers can easily print from your I-phone, I-pad, or computer wireless if you have your MiFi.
You may not think the need for printing would come up very often but it actually does for us. We do everything online, even our insurance, so when we get new vehicle insurance cards we have to print. It just seems like every week something comes up and you need to print something.
