Last time I was in Europe, those SIM data plans were cool if you stayed in the same country. But if you cross a border to a different provider (PTT), often the $20/megabyte rate starts up, just like if you brought a phone from the US: international data rates are insane.
Maybe this has been fixed in Europe, etc. We need WORLD data plans, and roll over data. One should buy a data package by size, not time (instead of size and time as we do now).
Oh, well ...
The $30/3months/1GB is not horrible for occasional use.
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Note that $5 for 24 hours is cheaper than many hotels charge for use of their WiFi...