Moto x - carrier question

[gjkiii]

I want to buy a moto x form motomaker and be able to use it on both AT&T and Tmobile. I was told to buy the tmobile ver and unlock it and then it will work on AT&T. I was also told not to buy the AT&T version because it does not work on all Tmobile bands. Is this correct information? Thank you.

 

[tbgb]

I want to buy a moto x form motomaker and be able to use it on both AT&T and Tmobile. I was told to buy the tmobile ver and unlock it and then it will work on AT&T. I was also told not to buy the AT&T version because it does not work on all Tmobile bands. Is this correct information? Thank you.

This is my understanding after researching - I switched from Verizon to Tmo when I got my Moto X and wanted the option to switch to ATT if the service did not work out.