What is the benefit to using a paper filter in a moka pot?

Moka pots are essentially percolators meant for making espresso. As such, they are normally fitted with metal filters inside the pot that are capable of filtering some sediment, but not oils or Diterpenes (such as Cafestol). Diterpenes have been implicated in cholesterol increases associated with unfiltered coffee, but may also have cancer- and parkinson's-fighting properties.

The paper filter will also have a large effect on the flavor of the coffee produced. Paper filters are designed to remove oils from coffee, but the oils removed by the paper filter can be a substantial source of flavor for the coffee produced, as many of the flavor compounds in coffee are fat-soluble.

Coffee produced with a paper filter will have less sediment, fewer oils and, in the opinion of many metal-filtered enthusiasts (myself included), a more even, less robust flavor. That shouldn't be regarded as an inherent downside, however, as many people prefer the flavor of paper-filtered coffee, finding the mellower profile and lack of sediment/oilyness preferable. Crema is more pronounced in metal-filtered than in paper-filtered coffee.

I just tried putting a standard paper coffee filter between the top and bottom chambers, and it worked great. My process, based on experimentation and research is this:

1. Pour cold water into the bottom chamber, just below the safety valve.
2. Boil the water in the bottom chamber. No sense in boiling the water in a separate pot. Starting with hot water before adding the grind cup is supposedly a good thing, so I'm killing two birds with one stone here.
3. Just as the water begins the boil, remove the bottom chamber from the heat. Careful from here on, as the bottom chamber is hot. I usually grab it with a towel or oven mitt.
4. Drop the grind cup into the bottom chamber.
5. Place a rinsed paper coffee filter over the top of the grind cup.
6. Carefully screw on the top chamber.
7. Place back onto the heat.. it shouldn't take long for the coffee to make its way to the top.

I noticed with the paper filter in place that the coffee came out the top a bit slower than usual, but with a lot more crema.

There ends up being zero sediments in the top chamber, which is hard to achieve otherwise.

Flavor is delicious, but I'm no expert.

For people with high cholesterol, there may be some benefits to doing this (if you believe that Diterpenes increase LDL). The paper filter can remove most of the Diterpenes from the ground coffee. It should also decrease any fine coffee sediment you get in the resulting coffee

I pour the coffee after mokapot into a filtered coffee dripper. The oil and other material left behind the filter. The smell of the filtered coffee is fresh bit caramel and smell of the oil and other residu left behind the filter is bad