Just took a trip to the eastern US and Canada, using a BB STV100-3. It is missing LTE bands 66 and 71, two bands which per currently-published specs the Pro1 also doesn't have.
The STV100-3 cell radio was basically unusable with T-Mobile in all of Charlotte NC, Virginia Beach and Syracuse NY. Upon return to the SF bay area, it is happy again.
frequencycheck.com claims B66 and B71 are both needed for T-Mobile. Based on my recent experience this is very true for at least one of B66 and B71.
Very much hoping a Pro1 version will appear which includes support for these bands. Until then, s