As the OP pointed out there are two options available for the KA; a roller/cutter attachment and an extruder.
The roller attachment would be my choice.
I own a hand crank atlas and it makes great pasta but it's a hassle to set up and since the KA is already in use to make the dough - it makes good sense to get the KA roller attachment. Also - that roller attachment is essentially the same as a handcrank atlas, EXCEPT that you can use both hands to manipulate dough.
The second KA option is the extruder. I have one of these and have used it twice. The texture of the pasta is just not quite right although it can make hollow noodles (like rigatoni). For sheets and flat noodles the roller version is head and shoulders above the extruder as far as 'mouth feel' of the pasta is concerned.
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