I've been listening to it for several hours, and it's traditionally "Bjork." After a few listens, I really dig 7 of the tracks. Not, "they're pretty good and easily listenable" but "these are awesome."
Especially "Who Is It." It's odd that it's the closest thing to a mainstream pop single on the album, but it's not dumbed down. Should it be released as a single with a video, it's not going to storm the world, but I think it'd create fans.
Production wise, most beats at first listen aren't easily recognizable as man made, unless you're specifically listening to the sounds themselves. They really have been tweaked into Bolivian, as my man Tyson would say. That said, there are a few songs where you can tell what is what. For example, in "Where is the Line" Rahzel's bass kicks and noises stick out to make an almost marching corps drum pattern.
Again, one thing that aggravates me is Tagaq's appearance on a track, in which after the midpoint of the track, I wanted someone to put a muzzle on her. Thankfully, it's just one track that she sticks out with her "talents."
Vocally, it's what a Bjork fan would expect, though the vocals are very raw in contrast to the beats. If anyone has heard Aurora from the Vespertine promo, and how her vocals were left untouched for the most part, that's what many of the songs sound like on Medulla. Almost sometimes sounding like first takes, which in this case isn't bad at all.
Overall, and this is just after several listens (considering it took me a little under a year to appreciate Vespertine to the point that I do now), she hasn't disappointed. After hearing a few snippets early on, and watching a bootleg concert in which she performed a couple songs, I was wondering if she was going to deliver. I think she certainly did.