Ok I have always used a metal strainer filter for brewing coffee.
We broke our glass pot on our Krupps coffee maker and couldn't find a replacment so we ended up going with a New coffee maker. The New coffee maker uses Paper Filter's. I have never been a fan of the paper filter. I have found that the Paper filter makes a stronger cup of coffee. I will explain
We grind the exact same amount of beans for the morning cup. We got a metal Strainer filter for the new coffee maker. I did a Test Paper Vs Metal Strainer filter,
What I found was the metal strainer lets the water flow threw the grounds faster and the coffee is weaker. The Paper filter holds the water in the filter a bit more and the coffee seems to pick up more flavor and is stronger/darker.
Bottom line is I don't have to use as many beans to brew the same strength coffee with Paper as I do Metal. Humm who would have thought.
This might be old news some of you just thought I would share my thoughts