I did a comparison of the choices on google docs for light users:
So far, it looks like airvoice / H20 are both reasonable choices.
PAYG Allows flexibility of going to very low usage mode, with min charge of $40++ per year.
Lower cost calls, probably a wash for data even if headline data rates are slightly lower at 30 vs 33˘ since min charge is 1˘.
Intl calls to a list of countries included with the standard minutes.
No intl sms.
Not considering tru as the 100KB min charge isn't that great when my phone uses 2 blocks of data according to ATT PAYG tool a couple of times per day.
True postpaid like roaming to 220 countries!
How are the web interfaces for H20/Airvoice? International roaming is also unclear!
If there are any other MVNOs with similar plans that should be included, let me know!