My operator made roaming outside the EU very expensive (EUR 35 for 1 week, with a limited amount of calls and messages, and 150 MB of data traffic, yes, megabytes). But being able to use phone normally anywhere in the EU, even if only with 3G, is great. Just have to remember to disable 4G.

I switched to a new plan after that rule came into effect and my new plan happens to be a lot worse outside the EU. I am not sure if this is a coincidence.