I made four Americanos from different sized Mukkas; results were essentially identical, large pot or small. The quality of the cup is highly dependent on the quality of the coffee. Due to circumstances I am drinking commercial "First Colony" Costa Rican whole bean from Williamsburg, VA, this week. Being kind, it is slightly above average commercial. I tried some regular moka in a Bialetti Express with it last week and it was flat, too.
Mukka instructions say to use milk only in the top pot. I subbed water and ran the machine as per cappuccino. All four pots tasted the same; less water in the north pot might have made a little difference. Milk and sugar added in the cup still left it tasting like McDonalds coffee with milk and sugar. Not bad. Not good. Basically, it made a marginal americano using marginal fresh-ground coffee.
I am certain freshly roasted coffee, freshly ground to espresso fineness, would have made a decent americano. A Mukka without proper grind would be wasted; Bustelo from the can would probably work as well as this mornings First Colony.
Mom moved in last year (she's 97) and, although she really likes good coffee, she occupies a lot of my (former) spare time; a problem exchange student from Belgium moved in last January; and I developed a pinched nerve in my neck two weeks ago. I REALLY want to roast some coffee but it's gonna be at least two more weeks before I get around to it. When I do, I'll try another Amukkacano. Absent good coffee I am sliding by on Percocet and water. Not all bad.