I look at a lot of ambient/instrumental type of albums as being like movies, as they set a sort of tone for the visual. Those movies tend to be the two hour or two and a half hour long movies, maybe three tops, but very rarely do they resemble the hour and a half movie, which is a spot usually reserved for comedy, animation and children.
In terms of movies, this is like The Godfather trilogy of ambient/instrumental music. The four songs are roughly 48/24/48/17 minutes in length and this is just really something you need to have the time and dedication to listen to—to truly explore.
I like this and I did listen to it all the way through. The only fault that I can really find with it is the length, as most people might not have that type of time to dedicate to a piece, at least even just maybe one track at 48 minutes, at a time, but hopefully the good people who really care about music will come through once again and weed out those too easily distracted or not nearly as dedicated.