On the other hand, international roaming has become so much cheaper now that swapping SIMs when you travel is no longer necessary. The legacy carriers still try to fuck you over, but MVNOs and dedicated travel SIMs offer amazing rates: I can get a year of roaming across 120 countries for around US$15.
It's a year of roaming of bottom-of-the-barrel backhaul, whose speeds and latency could make a 56k modem jealous. It is down to pure luck whether you get a route that works well enough to be usable.
You are always better off buying a local prepaid SIM at your destination airport.
There's also BNESIM who say they don't expire at all. I've only had one for a short time so I haven't tested that but so far it lives up to the promise.
