Significantly better car? Im not so sure. It was probably quicker, i think Button and Webber showed this well, but it was by no means significantly quicker. Lewis was only really quicker than Vettel in sector 3. In S1 they were matched, and in S2 Vettel was quicker.
Looking at Webber and Button, Webber hauled Button in pretty easily, but used his tyres in doing so. I disagree with the thought that Jenson looked after his tyres. He didn't, it was just a case of Webber burning his out!
A significantly better car is the car RedBull have had prior to Barcelona, and im sure there's few who'll disagree with that. Had Lewis got passed I doubt the gap would have exceed more than 3-4 seconds, if that is significantly quicker then what would you call the gap Vettel has had in the prior races?
Looking at the long run times, it's hard to pick out who's good and not. Sadly we didnt' see much of the Mercedes. The TV coverage was pretty shite imo, but we did see the other top guys.... The Mclaren's looked very able to pump in quick times with little steering wheel effort, likewise the RedBull and Alonso. Whilst Massa was chucking his Ferrari in all sorts of directions, though he was still quick!
At this stage, I would say the 3 most likely to get pole are (funnily enough) the 3 quickest drivers in F1. Vettel, Lewis and Alonso. I dont want to rule Webber or Nico out though, but tbh I cant see any other drivers getting pole, or front row. Those 3 just looked a whole bunch better.
"Trulli was slowing down like he wanted to have a picnic" LOL