I've been watching Google Fi closely. We had a friend on our boat two weeks ago with a Nexus 5 on Google Fi. There were times when we had great AT&T coverage (not a Google Fi partner) and he had no coverage. He actually had better service near Tortola than he did on the south side of St. John with only AT&T. Sprint has coverage on St. Thomas and most of the north shore of St. John. He was able to use my AT&T mifi for calls and data.

I have pinged folks on the Grenada Cruisers facebook group and there are a few people that are using Fi. T-Mobile global roaming is much more prevalent; it includes 2G data for international roaming, but islands islands no longer have 2G support and people are seeing 3G and LTE speeds with free data roaming.

Fi still only supports the Google devices. The Pixel is a nice Android phone.

I'm watching this, but AT&T is still a good option for us.

Cheers, RickG