The unlocked HTC U11 cannot be activated on the Sprint network because Sprint won't allow it. I tried because I wanted the Amazing Silver color option. Also had to return it. Don't understand why Sprint, the exclusive carrier, can't make the popular Amazing Silver and Solar Red color options available from the Sprint Website central warehouse and shipping location. No need to stock 4 SKU's (colors) in stores.
Truth - although not exclusive carrier, Sprint promotes iPhones & Samsungs.
Although the hardware is the identical including the availability of Sprint CDMA bands on both the unlocked and Sprint versions, the Sprint version has a Sprint specific ROM that utilizes Sprint's CDMA bands and Sprint's LTE Plus - Advanced three channel integration, a technology that bonds together bands of spectrum to create a wider lane, allowing more data traffic to travel at higher rate including great building penetration with the 800 Mhz band. No other carrier other than Sprint has achieved these speeds of 200+ Mbps in over 100 markets, thus far (mid July 2017).
If one could get the unlocked version activated on the Sprint network it would be crippled LTE without the Sprint specific ROM.