Picture it. McLaren are always there or thereabouts in the speed traps, and 9.9 times out of 10, is ahead of Red Bull in the speed traps. They also can generate loads of tyre temperature, which is usually a sign of an abundance of downforce. They matched Red Bull tenth for tenth in Hungary.
I think that actually now, the McLaren is the fastest car, bar none; except in qualifying, where their slightly less effective DRS bites them back.