McLaren have the best set up in F1, but their attitude stinks, well Ron Dennis' attitude stinks, and he IS McLaren.
Over the years they have gotten rid of the best brains in the business (Adrian Newey), and ended up with a clever committee. No singular person able to make that controversial but potentially great decision. This goes from car design all the way through to race day tactics. They rely on what the computer says. That is not a good thing to raw drivers like LH ....and of course Perez.
On the Mercedes front, I think Ross Braun will be able to provide LH with more power over the race tactics, allow him to go for that hard charging 3 stopper, instead of the McLaren safe 2 stopper. Time will tell.
For sure the genius that is Ross Braun will give Mercedes the upper hand come 2014 season.