He had one. Propensity for being knocked down before getting warmed up. A lot of punches that he'd just tank in the middle rounds could drop him in the first three.
I still wouldn't call his overall footwork amazing. It's just better than many in here give him credit for. It was at it's finest with guys in front of him.
Agree 100% on Frazier. He also dug the right hand to the body with authority and frequently. Frazier is also underrated defensively , especially when considering his aggressive fighting style.
Mamby definitely wasn't a speed merchant and generally relied on guile and positioning to avoid getting tagged clean that often. But I think the most underrated aspect of his game was his power. He had good timing and accuracy even if his technique wasn't always clean, he still hurt/stopped a number of guys with one shot throughout this career.