Like it or not he's better than Vidic. The Serb was aggressive and pretty formidable in an already dominant team alongside one of the other best CB's the league has seen in Ferdinand who was also a superior footballer.
The Dutchman is most certainly quicker, as strong as Vidic, just as good in the air but better on the ball and has a greater passing range.
However, what sets him apart is the effect he has had on that defence and their team as a whole. To go from being a side considered to have a dodgy defence to letting in 7(?) goals half way through the season is impressive to say the least.
Was head and shoulders above everyone else at Celtic so I surprised more teams weren't in for him when Southampton snapped him up.
Looked top drawer in an otherwise mediocre Saints side so there's a reason City were in for him too. If they'd have succeeded I think the title race would likely have been a one horse race for several years.
From what I've read he's clear favourite for POTY at present....