This is totally my personal opinion, but I do think it’s true that the US market in particular was historically not supportive of unlocked devices. I remember it being a “big deal” when Google sold the Nexus One unlocked and direct from their site.
Some of the systems from that era are still in play today - for example, going into a Verizon store, they’ll tell you that there is no compatibility and refuse to sell you a SIM if you say it’s for r1, yet we’ve confirmed they do work.
This is less of a problem elsewhere in the world - I don’t see many people talking about sims not working in Europe, for example.
Just adding a note that we’re already seeing users have issues with SIMS cards that had previously been reported to work. It would be good to have the clarity that @mattdomko indicated in this thread.
Ireland update - I’m using a 3 sim at the moment (three.ie) Tried it in the R1 first and (with wifi off) just got “connecting…” Inserted the sim in a phone and turned on. After a few minutes got internet on the phone. Switched back to the R1 and connected to teh internet first time. No issues over the last hour or so.
I just tried Vodafone (only data) and it works.