I had an old Mr Coffee machine and it uses a filter in the shape of, for lack of a better word, a cup.
I went out and got a new Mr Coffee and this one uses a cone shaped filter.
(of course now my old filters won’t work 
)
Anyway I was wondering is this purely a design thing, or is one shape better than another?
I’ve had both and in my experience the cone filter produce a richer, smoother flavor and seem to require less coffee.
With the cone shaped filters, you can grind the coffee extreamly fine, which allows you to use less, as the greater surface area is more efficient. If you try to do that with a pleated filter, the pores will plug up and the basket will overflow all over the counter.
Flatten the pleats on the cup filter. You should have a large circle of filter paper.
Fold circle in half, then in half again. Pull open one leaf to form cone filter.
Laugh at the man.