Difference between AT&T and Verizon iPad 4G

Question

Is there anything fundamentally different in terms of hardware between the AT&T and Verizon iPad? I'm aware that once you choose one you're unable to use the other, but is that a software configuration or a hardware restriction?
The iPhone differed in that the AT&T was a GSM model while the Verizon was a CDMA model. The CDMA model cannot be used internationally. (Is this conceptually similar to the iPad differences?) Since I'm not a US citizen and want to be able to use the new iPad in my own country's 4G network, I would like to know whether I'm confined to the  option of buying an AT&T iPad to ensure that the 4G LTE connectivity works at home too.
Apple seems to make it clear that each iPad is capable of connecting to any network up to 4G LTE... but is more ambiguous about the differences between the AT&T and Verizon versions. I would like to seek some clarification before commiting to buying an iPad that wouldnt work on international 4G networks!

Answer 1

This is the first iPad to offer both CDMA and GSM on Verizon.  The following is based on my experience with Verizon's global Blackberries (CDMA/GSM) and my AT&T iPad (GSM).
If you travel internationally infrequently and for short periods of time (i.e., the annual two week vacation), you  probably won't bother to go through the hassle of buying and swapping out the SIM for a country specific card.  For short term use, the simple solution is either of the international roaming plans offered by AT&T and Verizon.  The AT&T international rates are a little lower than Verizon's but I'd recommend Verizon if you have better coverage domestically with Verizon. 
If you travel frequently and are likely to  swap out the SIM, AT&T is your better bet. The extra LTE band is a plus.  More importantly, their customer service folks have much more experience handling questions about GSM and international roaming.  Verizon's business is mostly domestic and CDMA. They've offered a handful of phones with dual CDMA/GSM, but this new iPad will be their first major foray into GSM and international roaming. 
As for CDMA coverage, that's useless in most of the world - except China.  But, with CDMA, you're stuck with the Verizon international roaming rates unless you want to go through the hassle of opening a data account directly with China Mobile.  China Mobile is Verizon's roaming partner in China, so either way, you're stuck with their funky version of 3G unless you switch to GSM and get a China Unicom sim (and you're back to AT& T because they have the experience with GSM).