Bialetti Which Size What Size Bialetti Stove Top Espresso Maker?

What size Bialetti stove top espresso maker? - bialetti which size

I wonder what the size of the purchase, 1 or 3 cups? I usually only 1 cup for me because I have seen myself, but just ask if you could make a big difference when you only have one cup 3 is a place (for me to do coffee welcome to occasionally curious) and use only small amounts of coffee / water 1 cup of me? Does this work? Would this effect the taste?

Thanks