Google Fi service for hotspot

We have had Project FI now Google Fi for several months now. We are presently in the Yuma foothills area and I can see the T mobile tower that I am connected to. When calling anyone they consistently complain that either my voice is garbled or they can't hear me at all. I on the other hand can hear them just fine. Data wise things seem to be a lot better the hot spot seems to work just fine. Google is pushing something though as our data usage has jumped from about 7 gig a month on Verizon to about 25 gig on Google Fi.

Nice thing about Fi is they cap your bill at $60 iirc if you use a lot of data. Use less, pay less. Includes international data too.

Bad thing, at least for my area they use Sprint towers which are very poor round here.