Wlad Top10: Beat many contenders, including the best of his era, dominated during 6 years. Vitali Top15: Great comeback, barely lost rounds, plus wins over several contenders (not as many as Wlad)
Wlad has the better wins, but he's also been knocked out three times by mediocre opponents. I'll go for Vitali.
Id say Wlad has the better chance of being the better but ATGwise there's a problem when the top 2 fighters refuse to fight each other while splitting the contenders