Is it one of those cars that alters the brake boost depending on circumstances?

That drives me nuts. When you put x amount of force into the brake pedal, you should know you're going to get y amount of deceleration. Don't double the brake boost just because you decided it's an emergency due to some opaque criteria.

> Is it one of those cars that alters the brake boost depending on circumstances?

No, it's just breaking a bit too hard for you while the panel beeps and has scary red lights pop (that you'll have a hard time reading).