@Nezgar @dust2dust
I think pm's roaming agreement with AT&T expired or is otherwise in limbo until VoLTE is implemented and a decision will be made at that time on whether to renew their agreement? This is speculation of course and I don't have the history of the origins of pm offering U S roaming add ons.
But thru my research I learned at the time of the 3G shutdown in the US T-Mobile's 3G network coverage was a pitiful 21% of the country and one of the reasons they maintained their 2G network for customers to fall back on if they did not have a 4G capable device. Once AT&T decommissioned their 3G network their main purpose for roaming in the US was eliminated.
With At&T's 4G LTE network coverage only 6% more nationwide than T-Mobile's (68% vs 62%) and T-Mobile able to offer a viable network for voice services while awaiting telus foot shuffling on VOLTE it makes sense to shelve AT&T as a roaming partner. If you are only paying for one roaming partner offering US Roaming add ons that are good for 50% more days (15 days from 10 days) at the same price and larger data buckets for nominal price increases makes a lot of sense now.
When you look at the network coverage maps of the 3 major networks in the US (Verizon 71%, AT&T 68% and T-Mobile 62%) they all offer fairly comprehensive coverage in the east and good coverage in population dense areas in the west. None of them offer particularly good coverage in rural areas especially evident in the western states with some states very underserved.
As far as recommending pm customers use a "local" Sim card whether it's from one of the 3 major network operators or one of the many MVNO's operating in the US they cannot offer better coverage than pm 's roaming add ons only better coverage of voice services via VoLTE and in some cases better pricing. The issue of connectivity in rural or low population density areas of the US will remain. The only real exception would be Alaska where customers are better served getting a CGI Sim card as they offer the best coverage in that state compared to any other provider.
