That fight with Vitali really proved his weaknesses and he was known as a guy who could outbox anyone and only lost if he got luckily KO'd.
I think that fight might do more for Vitali's legacy then Lewis's even though Lewis was awarded the w. The Vitali fight does not move Lewis up or down in the rankings imo. He did give Vitali one of his toughest challenges though, which is something to consider.
The way you word the question almost makes it seem as though you think the VK fight hurts Lewis' ranking.
True, no one has tested Vitali the way Lewis did in that fight. That has to be worth something now that I think about it more. I am of the opinion that Lewis was outboxed, but still he made it competive.
He is already top 5.... and meeting Vitaly.. why would that have any negative impact? Fact is - it had none. The fight showed that they were very evenly matched (perhaps with Vitaly slightly better, but he was also younger). That means that Lewis would still had been champion today (if there were no Klitscho). So in that sense it gave LL a ticket to believe he could be dominant in this generation too.
That fight also didnt change anything. If anything it showed that Vitaly was vastly better than Byrd... and that Vitaly can get injured (in other words that he is human... if someone thought he was a robot..).
His disgraceful glass heart got exposed when he quit on his stool, after getting walked down and beaten up by a blown up SMW.