The Somberlain, IMO, is not as accomplished as SotLB. Don't get me wrong, The Somberlain is still a classic. And I strongly recommend getting it. I think Century Media is re-releasing it in the upcoming months.
The Somberlain does possess some songs that are equal to some songs on SotLB.
Overall, The Somberlain is not as good as SotLB, but is still leagues better than the majority of the dross coming out of Scandinavia these days.
I recommend getting it. If you like SotLB, you will like The Somberlain.