Pardon my ignorance, but as I understand it, these $5 a day...

Pardon my ignorance, but as I understand it, these $5 a day roaming plans allow you to use up your plan allowance while roaming, at differing rates depending where you are, and these could be quite high. And I think you are charged for calls received also..

Corona on the other hand will utilise the PSTN - regional landline telephony networks as well as short haul VOIP networks. This is by far cheaper than roaming on cellular networks and apparently a lot better call quality.

If I am not wrong or too simplistic, as I see it there will be enormous savings using CORONA.