Really was pretty even I'd say, Sergei had the edge technically but Aleks speed was causing him problems, Sergei tapping his chin was not an issue in that fight either, Aleks did not catch him doing it he caught him a second or two afterwards when Sergei had reset.
Post Pride really Aleks went off the rails quite fast, maybe due to not being able to fight in the US(for Hep or criminal record or whatever it was) or just because he started drinking again, went progressively downhill whilst picking up easy wins for a few years then started to lose.
Ironically Aleks today actually looks in pretty decent shape physically, technically he's dropped off(grappling seems almost non existent now) but not training much during his mid career probably kept him in better shape than Sergei or Fedor.
Better shape = less mileage you mean right?
He wasn't quite reset if he did 0 effort to avoid that punch, like when yan switched stances VS omalley, he was reset but not ready and he ate a huge punch.
As far as speed goes i don't remember sergei struggling that much as he was comfortable winning most exchanges both on feet and grappling. I should maybe watch again its been over 15 years lol