The NATO called “Bison” have been defined as an utter failure. There are some food for though anyway. This advanced design was conceived and completed in less than two years, and entered service before both the B-52 and Tu-95. On the technical side, the M-4/3M and the B-52A had a broadly similar performance. Granted the B-52A had a bigger payload/weight ratio, higher service ceiling and a slightly longer range, but the real asset of SAC was its tanker force, something the DA lacked badly.
And don’t forget that after its short life as a strategic bomber the M-4/3M tanker (con)versions -like this one- provided vital services, palliating in part that DA’s weakness.
Not bad for a failure….