As you may know

I'm no fan of Vettel, but I'm not surprised he's pissed off: this is meant to be his party but, today, of all the people to piss on his fireworks, it's Mark. Well, it's tomorrow that really counts and, while I'd love to see Mark's career go out with a bang, I still expect Seb to win.
As for TPJF's point about the Red Bull being optimised for Seb, of course it is! RBR were openly saying that would be the case three years ago. So Mark's driving a car designed for Seb but he has known that for a long time now and has still re-signed to stay on there until now. If he wanted equal treatment, he could have gone elsewhere but he chose to stick with the best team which, on the other hand, he had been with since they were nothing.