I replaced my booster with 2 or 3 FJ60 boosters and it never really changed what I was experiencing. I too am getting an rpm drop generally when I press the brake pedal. But I had a hard time believing that 2 or 3 separate boosters would all be bad, so I'm just running with it for now (have for about 3 years now), checking the spark plugs occasionally to see if the cylinders look like they're running lean.
I dunno...
I dunno...
