Unfortunately, I found the source of my FPS woes. It seems its actually my save file that is doing it... I started a new character, using the ST Robot Race mod, and I found my FPS to be excellent. I then loaded my older save, using the DK custom Caucasian, the massive stutter is back... I wonder if there is a save scrubbing tool or if FNVEdit can help cleaning the save. I recently reinstalled the game, so I think it might me a missing mod or something. Any help would be welcome.