you must have had a bad check valve or booster. i tell you FACT, my brakes are AWESOME with 7" . it wasnt too bad before I put the vacuum resevoir in. it worked but if I was in traffic, I could feel it after a few steps on the pedal.

now, I dont notice it a bit. but then again, I dont drive in traffic where I am stopped for a 1/2 hour or more