Well, I'll agree that Agalloch are good, but I don't think they come close to being as emotional or original as Enslaved. They both have a sound that is based on repetition, but Agalloch seems to overdo it for me. Cool riffs, but way to simple, and they go on for way too long. Enslaved, however, take a simple, awesome melody, and often make little changes to transform it into a an almost totally different, yet equally majestic piece of music. Agalloch seem like and amateur version of Enslaved mixed with Opeth sensibilities to me.
And I thinkit's cool that you think Monumension is the best LuminousAether. I think it's probably their worst as a whole(despite being better than most metal records ever released!), in terms of their proggy albums, ie. Eld to BTL. I've never seen many Enslaved polls, I wonder if they reflect Opeth album polls, where there is a huge following for each album. In my opinion, that's the sign of a geat band, many fans, but each loving a certain album for it's particular uniqueness.