For filters I like paper actually! It cleans out some stuff that makes the coffee taste worse imo. And I vaguely recall studies about coffee and health drawing a line between filtered and non, where the negative effects (aside from caffeine) basically go away if you use a filter.

Basically there's 3 spots where there's plastic and it's not my favorite:

• The water reservoir. I wouldn't mind if it were temporary, so I could work around this if it were the only issue by just keeping it emptying and filling it when I want coffee. But otherwise the water sits there for ages slowly picking up whatever leeches out (this is cold water though).
• The shower head thing. The water is drawn out / pumped in a pretty ingenious way and the main parts after the reservoir are metal, except the head where it sprays the water out in various directions. That's just black plastic! And the water is very hot at that point, boiling.
• The filter basket. Again just black plastic with near-boiling water.

It's one way to get exposed to endocrine disruptors every day, basically.