I ended up switching to Mobile-X since I'm on wifi so much I only use a few gigs of data a month. $2/month + $1.90/GB vs Google Fi's flexible plan of $20/month + $10/GB.
Having moved here from the UK where I was used to cheap mobile plans I just grate at how extortionate they are in the US.
If you travel internationally, they're really cheap relative to everyone else who will charge you absolutely ridiculous roaming fees.
The Google Fi plans with roaming are either $65/month (100GB) or $20/month + $10/GB. I often end up using quite a bit of data abroad.
The single place I noticed verizon gets coverage and tmobile doesn't is three levels underground in a concrete parking garage.