Default [Q] Moto G to Moto X on Tmo - help me not make same mistake

My Moto G on US version won't work on the faster Tmo (AWS) bands, I get 21-5 meg if I'm lucky. My cheap Lumia gets 10-15 meg, and the speed difference is noticable

If I get the GSM TMobile version of the Moto X - will i see the same issues? I checked over the spreadsheet that lists all the bands, but I did that (I thought) with the Moto G and still it doesn't work.

Thanks in advance!