If anyone was wondering this phone has Bluetooth 4.0 not 3.0. Sprint made a mistake on the fact sheet. Both HTC website and the FCC filings shows Bluetooth 4.0. Took this screenshot from a special hidden menu shows it has 4.0.
I have the Band and it works great with the 8xt. I'm on WP 8.1 and having no issues. The app can occasionally take a bit to load/sync with device. Probably would do better on a more powerful device but overall runs solid on 8xt