JMM is a good fighter but lets be real here, he is over shadowed by the 2 big super stars in Pac and Mayweather. Losses to John, Mayweather, Bradley and Pac left him without a lengthy period of dominance during his best years, never going much more than 2 years without having a loss pop up on his record. While Pac went on a 7 year undefeated streak in his prime and Mayweather is still undefeated. JMM has had some good wins but he will mainly just be remembered for fighting Pac. Just like how Norton is mainly remembered for his fights with Ali.
without the pacquiao fights, jmm is just another good boxer. yes he ko'ed pacquiao but he's already the 3rd boxer who had done that to pacquiao imo vlad or hopkins has better achievement in this era than jmm