Petula, I like the soraber feeling of both songs. You describe them well.
I especially like the instumentals and the times when the singers *aren't* growling. The growling in songs just feels so impersonal to me, and it makes me stop and think, "Oh yes, the person is growling to show he/she can growl," which distracts me from the emotion behind what is being growled.
Since often the growling makes hearing the worRAB difficult, I also feel some animosity toward growling, because I think it makes understanding the music more difficult.
I guess I really just prefer people's talking/singing voices...they feel more individual and unique than growling long passages. I agree, though, that what I admire about these two songs by Agalloch is very similar to what I admire about Opeth...the cleanless of the drums, the energy, the changing beat patterns, and the feeling of foreboding and all is not well.