Master or Booster?Help!

[Railing68]

The Pedal doesn't feel super firm in the initial couple of inches when the car is running and still getting a hiss, but brakes will lock it just seems to take fair amount of effort. I am thinking about switching boosters due to inconsistent pedal feel. Is this the common problem with vac assist? Would a dual diaphram booster be a better option, and how much does the diameter effect assistance? I road tested and seasoned pads in, it got considerably better but I am not 100% satisfied with the inconsistent feel. Also the cover to the master is leaking and I wonder if this is partially due to the angle of mounting from the booster. I don't know if the MC original orientation was level I presume it was. Any suggestions would be greatly appreciated, SS