I'm very confused by the whole T-Mobile thing. Is one version between the Sprint, T Mobile, At&T or Verizon iPad Air more desirable for resale down the road or give you more options to pick and choose between carriers? I plan to only use the cellular for the 5 winter months when I go away on vacation and plan to use it in the event of spotty wifi access on the road. The T Mobile deal sounds appealing but someone mentioned buying the Tmobile version but putting in a verizon simcard. I didn't think there was a slot on an iPad to insert a sim card. Ugh. Totally confused. Please help.