All iPads iPad cellular unlocked?

[edtorious]

I never had a cellular iPad before. Those carrier plan, they are month to month right? No contract and can cancel anytime? Can I buy a Verizon iPad and still use AT&T and Tmobile sim card? And vice versa? or Verizon iPad on CDMA only? Can I use prepaid sim cards like Straight Talk or AT&T GO? How do I go about using those in the iPad? What is the best data plan and which carrier?

 

[JackieInCo]

They are all unlocked. I use my current Mini with AT&T and T-Mobile all the time. Plans are month to month.