Best Master size?

[Mr Gazza]

Okay, this might all be slightly academic. I'm trying to get straight in my head which would be the best piston size to go for to operate a single Brembo Goldline four pot calliper.

The benchmark is my twin Goldline setup on my M900Sie with (I think) a 16mm master piston... I just can't conceive of a better brake. I achieved some unbelievable stopping distances on a machine handling course last year.

When I fitted twin discs to my 750SS many years ago, I retained the standard master and observed much more lever travel after the conversion. This was good as it improved the feel and sensitivity of the lever with double the braking power.
I don't know what size a standard single disc master is on a 750SS?

I am assuming that a larger master piston.. Let's say 18-20mm would render very little lever movement feeding a single calliper and would probably be rather unforgiving to too much insensitive use? Probably giving very little feedback?

Presumably larger pistons have come about as the capacity of the callipers has increased?
It seems important to me to balance the master to the calliper(s) to achieve the correct ratio of power to feel.

My thinking is that a smaller than 16mm master would be what I'm looking for?

Thoughts greatly received..