One little-noticed upgrade to the AT&T iPad 2's 3G radio will make a big difference to many users outside the US and international travelers: the refreshed tablet now supports quad-band UMTS, like the iPhone 4. The original iPad, as well as the iPhone 3G/3GS, only had tri-band UMTS, omitting support for the 900 MHz band common in Asia and parts of Europe. The Verizon model's CDMA radio, on the other hand, is compatible with very few carriers' networks worldwide, making it a poor choice for globetrotters.
One of the complaints about the iPhone 3G, and its successor the 3GS, was that it supported only AT&T's 850 and 1900 MHz UMTS bands, and the 2100 MHZ band used in Europe and Asia. Many carriers in Australasia, however, use the 900 MHz band, especially in rural areas, and since the European Commission opened up the 900 MHz band in 2009, carriers in Europe expanded their offerings in that frequency range as well. 900 MHz is attractive in less populated areas, because lower frequencies travel further and penetrate buildings more easily than the higher frequencies do, which means carriers don't have to deploy as many base stations. As a result, when the iPhone 4 included support for the UMTS VII operating band, it came as a relief to users in these areas. Previously, the best available to users of these carriers was slow EDGE or even GPRS service.
The GSM iPad's inclusion of 900 MHz support, then, means that the same device can be used with many carriers in Europe, Asia, and the Antipodes, where Vodafone offers rural 3G coverage using 900 MHz in Australia and New Zealand, The Verizon iPad may not be the best choice for international travelers, as its EV-DO Rev. A radio isn't compatible with many systems. However, for people who travel mostly between the US, Canada, and Mexico, the Verizon iPad should work just fine, as CDMA is fairly common in those countries.