Earlier quoted context omitted.
I have T-Mobile's Simple Choice plan, and while I haven't flown too much internationally, the few times I have, my service has worked seamlessly. My plan includes 4G coverage in Mexico and Canada, and 2G coverage in 100+ other markets (with the option to upgrade for 3G and 4G rates in those markets). Looking at [1] it appears the current plans may not offer this for free anymore, but it's still available. [1] https:/…
I believe the above commenter talks about the ease/pricing of Fi as much as the experience. I'm using Fi on my iPhone (and have for a while) - and it works worldwide for $10 / 1Gb. It's actually downright magical compared to other offers (even the Apple SIM powered ones).
If you can actually get these plans using Apple SIM - it’d be order of magnitude cheaper.