Originally Posted by PropellerHead

I talked to my buddy who is a BMW master mech at the dealer here- he worked for my Indy before that. Really a good guy.

He said that the X5's master cylinder is balanced in an 'X' configuration wherethe front left is 'connected' with the rt rear and vice versa. This allows the master cylinder to send the rt amount of fluid/pressure across the chassis so that one wheel- or set of wheels- will not be out of balance with the others. Pretty smart. Of course, this is not done on the basis of future brake upgrades, but to balance out the system as it wears pads and rotors at different rates front to rear.

I did jut put six pots on my X5 and it is very firm. The pad surface area over my previous StopTech 4 calipers is very big even though the rotors are the same size.