At the time of their fight; Vitaly had the highest KO % of any HW champ, unless I'm mistaken. He definitely could bang, Briggs vs Lewis was a war of the chins until Briggs gassed out in 5. He took some ugly punishment against Klitscho.
Having a high stoppage ratio doesn't necessarily correspond to massive single shot power. Vitali could bang, but it was his workrate and connect ratio that ended his opponents, rather than his ability to put fighters' lights out. Fighters that are able to register the damage of a shot are more likely to remember the pain they received from the shot vs a shot that puts their lights out.
I recall an interview with Vitali after the fight and he said he was talking to his training team and he was rather upset why he couldn’t knock Briggs out He said they were going to start putting effort into altering his punching form to increase his knock out power, because he really wanted to put Briggs out but was frustrated why he couldn’t
Imagine foreman landing the same amount of punches on Briggs Laughable, vitali is an arm puncher who’s punches sting.
Foreman landed 230+ punches on Briggs the night they fought. But he was slow as molasses at that stage.
Both Vitali and Foreman have overrated power, Vitali moreso. The hardest puncher Briggs ever fought was Lennox. I don't need Briggs's sayso to know that.