that one is my favourite. all-time favorite album in any genre, possibly. i can disappear so deep into that one. simultaneously more dark and horrifying than any metal and more ecstatically beautiful. it's based around milton and it's totally worthy of the comparison.
i think all of their first five albums are worthwhile (didn't get into the last one). THE UMBERSUN is actually the third of a trilogy, the second of which is probably my second favourite of theirs, though it's kind of amateurish and midified which puts people off.
their later work is more polished, probably more experimental but ultimately more streamlined in composition, not as rich in mood and texture. WINDS DEVOURING MEN is maybe their gentlest album, it's good but reaches more modest heights. some parts of SUNWAR THE DEAD are actually really rousing, i'd say they were metal as fuck if not for the fact they aren't metal at all. i can imagine them appealing to some folks here in any case. examples:
most headbangable fucking neoclassical music ever. that climax at 2:40-3:00 of the first one is absolutely spinetingling, and the kind of thing they do pretty regularly on THE UMBERSUN. last 40 seconds is fucking amazing too.