Examples of what I'm looking for: Stuff like Colour Haze (not really metal, I know), Jesu, Alcest, Nadja, Umbra Nihil, Fleurety's
Min Tid Skall Komme, The 3rd and The Mortal's
Tears Laid in Earth (for it's uniqueness and jazzy feel), Neurosis and Isis (in the way they hold back a lot to build tension).
So it's not really a common "sound" or "theme" per se, but a common approach. I'm going to change the name of the topic (if I still can) to simply "subdued experimental metal". Metal that doesn't go right for the juggular but hangs in the air and slowly evolves and/or occasionally explodes.
My Dying Bride is not what I'm interested in, I really can't stand that band, especially the singer. Early Paradise Lost is good, but not really what I'm looking for here. Also, Draconian falls into the same uncomfortable area as MDB for me.
I suppose Agalloch and Empyrium fit the criteria here, so if you want to recommend more bands like them, go ahead I suppose as it can't hurt, but for some reason I don't feel like they quite fit with the other recommendations, maybe because they're so familiar to me that they don't seem experimental anymore
edit: I really liked Flood...does anyone know where I can buy a non-import copy though? I really can't spend $35 + shipping on one cd.