I mean people forget that when they first came over that it was pretty much a consensus that Wlad was the better one and would be the one to become the next heavyweight kingpin because his skills were just that level above Vitaly's.
2003/4 with Wlad dropping those two fights and Vitali having that war with Lennox flipped things for them.
See
Before Wlad/Sanders and Vitali/Lennox none of this was being said on message boards.
Once they both faced different types of adversity, I think most would agree what in a hypothetical fight between the two, Wlad pieces up Vitali all sorts of ways but Vitali doesn't go anywhere and eventually stops him.
Against a neutral opponent though? I think Wlad is better. I think Vitali really saw the benefit of their being a lack of skilled boxers in the division. Dude shouldn't have been able to walk around with his left arm at his side hitting the shoulder roll on people