Just posting the sha sums for SurfacePro4_BMR_155_6.6.0.zip incase anyone needs to verify their download.
SHA1: SurfacePro4_BMR_155_6.6.0.zip 5F3855D75B0E942A58407C327EDB068E97DDDAEB
SHA256: SurfacePro4_BMR_155_6.6.0.zip 54FD7BD42957FAE4ADAE1F5EEBF1F398A98D9784F8D47EADFCBCA0E865F5559C
SHA1: SurfacePro4_BMR_155_6.6.0.zip 5F3855D75B0E942A58407C327EDB068E97DDDAEB
SHA256: SurfacePro4_BMR_155_6.6.0.zip 54FD7BD42957FAE4ADAE1F5EEBF1F398A98D9784F8D47EADFCBCA0E865F5559C