For a few years now I have been using THREE as my mobile network provider.
I switched over because of the ‘Feels Like Home’ feature they offered and the fact that I could get high levels of DATA use included in my tariff.
I have used this service in a few countries now and my only beef is the availability of 4G. I seem to get 3G at best and for some uses it just does not cut it. Having said that its great to use my iPhone as a SAT NAV when driving abroad.
Recently, in Europe, roaming mobile phone charges have been scrapped and users can use their ‘home’ contract at no extra charge (fair use policy applies). This means all other providers now offer effectively a ‘feels like home’ service. Not sure what the post-BREXIT tariffs will be like though.