Regarding Doom and final doom, both played very well via system link. I beat both on co-op with my brother years ago. I have all those things needed, including two burned copies of Master edition, two ps1s (both scph-7750) with TonyHax memory cards too. When i set it all up and select coop on both systems, it just sits there. On doom and final doom, it usually connects within 5-7 seconds.