Just looking at pure speed on the track though, for me, Vettel is up there with Senna. Yes, the RBR is a great car, but you only need to cite Monza 2008 as evidence that Vettel doesn't need a great car to show what he can do. 2008 reminded me of Senna at Monaco in 84 or Estoril in 85.
The greatest similarity is their qualifying pace. The commitment and control is what separates these two in my eyes. I don't think you can hold it against Vettel that he doesn't win from pole! He is not giving himself a great chance to fix that perception right now, is he?
The other factor is Webber. Mark's record in qualifying vs his team mates was exceptional until Vettel arrived and now he looks second rate.