It's the gear that you don't even think about that is sometimes the most important. Ever since I signed my first contract with a mobile carrier I have hated ALL mobile carriers. This changed the day that Google announced Project Fi (now Google Fi).
I switched from my iPhone 6 to a Nexus 5X just so I could use Project Fi, but ended up missing iOS too much and eventually went back via Virgin Mobile which seemed like the least crappy option for an iPhone carrier at the time.
I started reading about people getting Fi to work with iPhone provided the SIM was first activatd on an android device. After returning from a trip to France, where I dropped $60 for 10 days of local data coverage, I was ready to give this a try. Aside from voicemail acting weird (why does this still exist?), everything seemed to work great! There were limitations of course; without proper hooks into the OS that Project Fi had on android, network-switching and wifi-calls didn't work. I could make a call though and more importantly, data worked fine.
Much to my surprise, just a couple months after I had been unofficially using my iPhone on the Fi network, Google officially opened up the service to iPhones! The app and service are still a bit limited compared to what you would get using an android device on the service, but it's great that Google is expanding the network. The service works great and I love knowing that wherever I land, pretty much anywhere in the world, I'll turn on my phone and be greeted with an active data connection at no extra charge.
Google Fi removes the additional hassle and expense of having to buy and activate a new SIM card every time I travel internationally. I can now (again) land and walk around my camera and phone and be confident of where I'm going and what to expect thanks to a reliable connection. It makes the world feel a little bit smaller and all the more explorable.
If you feel like trying out Google Fi, use my link and after 30 days we'll both get $20 off our bill (or don't, it's up to you, but do give them a try!!).