If you’re still trying to decide on which carrier you want for your new iPad your decision just got a lot easier. The Verizon 4G version of the new iPad will work on AT&T 3G and “4G” as long as you have an AT&T micro-SIM to put into the tablet.
The Verizon iPad has an unlocked micro-SIM slot, which means that any micro-SIM should work if inserted into the slot. So if you have an AT&T micro-SIM from an iPhone or iPad you can just take it out of your device and pop it into the new iPad. With the micro-SIM inserted you’ll be able to get “4G” HSPA+ data from AT&T, just not LTE.
It’s surprising that the Verizon model wouldn’t have a lock micro-SIM card slot. But since it does it means that the Verizon model is the model to get if you want mobile data on your iPad.
With it you should have coverage pretty much anywhere you go in the US. Just pop in the AT&T micro-SIM when you’re outside of Verizon’s network, and take it out again when AT&T’s network is lacking.
By getting the Verizon version you won’t sacrifice any speed in an LTE area. In our testing Verizon and AT&T’s LTE networks are both really fast, though AT&T’s 4G LTE network is much smaller. Although, in areas without 4G LTE, AT&T can be faster, assuming the network isn’t bogged down at all. The video below shows Verizon 3G vs AT&T 3G, with a big speed advantage for AT&T.
Presumably the unlocked micro-SIM slot in the Verizon iPad would also make it easier to take overseas. We haven’t been able to test it, but it would make sense that you’ll be able to put in a micro-SIM from a local carrier in the country you’re visiting to get 3G data there without any of the penalties you’d get using a US carrier in another country.