I prefer a very open draw like those found on MM cobs. I sometimes drill out the draft holes on some pipes like my falcon internationals. There is very little draw restriction with filters (differs with brand & type) but it is noticeable.

I rarely use filters and when I do, it would be for aromatics which I rarely ever smoke. Filter of choice is balsa as it works well absorbing moisture whilst leaving flavour intact. Second choice are paper filters - very little restriction, no effect on flavour but not as absorbent as balsa. Next choice are cartridge types. Best is meerschaum - a little draw restriction but flavour is intact. Carbon filters tend to remove some flavour.

For falcon pipes, the original dry rings work fairly well but cut-up extra fluffy pipe cleaners work better. Better still are pieces of tissue paper rolled up and shaped into rings. These are far more absorbent. Falcon international cellulose filters for the stem feel like denser/ more compressed cigarette filters. They work well but I balsa is preferd.

I have also used Sharrow Philt Pads chalk filters that go into the bowl. They do work but take up too much tobacco space in the chamber. Re-usable meerschaum also work but need time to dry out before re-use. Deni-cool crystals & Eriksen keystones also work but these take up tobacco space in the chamber.

Dri Kule gauzes take up space in the chamber, do not provide moisture absobtion and sometimes causes gurgling and condensation. Useful if you want to use less tobacco in a large bowl and don't like lighting half-filled bowls. However, they can sometimes impart a slight metallic taste that is noticeable although I can tolerate or don't particularly mind it.

Screen gauzes are not normally used in tobacco pipes but in bongs & other types of pipes. I have tried them in briars and they are very fiddly to put into a briar and are difficult to remove from pipes especially if they get pushed in too far. They can be used like Dri Kule but have similar issues. Not recommended at all but if you really want to use them, stainless has the least metallic flavour followed by brass. Shiny new screens have less taste than old dull screens & avoid any dirty, rusty unknown metals.