LTE T-Mobile Global Data in Canada
My iPhone 6 Plus connected up to Rogers LTE data after about an hour in the country and then retained that connection until I left.
My iPad Mini 2 defaulted to Bell 3G, but when I manually selected Rogers, it also grabbed an LTE connection that worked flawlessly.
Even at throttled speeds, the LTE connection really seems to make the T-Mobile data usage globally reasonably fast.