Unlocked One X?

[dh80]

Does anyone know for sure if an unlocked One X from Canada will work on LTE? I've heard people mention it but dont know if anyone has tried it. I also heard that an unlocked One X will probably cost $650 where you can get it from AT&T for $550. Is there any benefit to paying the extra cost besides being able to take it to T-Mobile also?

Last question, I have an iPhone 4S and if I was to get an One X which plan would I need to be on to use both phones? I heard if your not on the right one something happens with voicemail..

Thanks in advance