I somewhat doubted that I could really like the record, since I never liked Belle & Sebastian. A single spin of the record blew all those worries away (well, most of them). The first song "Deus Ibi Est" is one of the best of the record. It's mainly a drumbeat, a chord and Mark Lanegan/Isobel Campbell singing. Simple and yet very intense. Lanegan/Campbell does work indeed. And that's the point: "Black Mountain" is sung completely by Campbell, and to be honest, the song is just too...feather-like. It lacks this heavy, dark voice that perfectly counterparts Campbells voice in the other songs. Same goes for "Saturday's gone", although this one ain't as stressfully floating as "Black Mountain".
Anyway, I recommend you give the record a try, it is worth it.
If you wanna listen to (the fantastic) Ramblin' Man, click here.