At first I was horrified by this, but it mellowed out over time. Definitely mushroomy, buttery-then-earthy, some burnt caramel sweetness. Otherwise intense in roast and over-syrupy in a way I kind of expect from this Stillwater/Mikkeller/Evil Twin bunch. It's a strange mix of flavors and never settled into a comfortable place for me.
Inky, black stout, but very tasty - about as good as you can get with a straight Imperial Stout. It's been a while, but I think this is comparable to Dogfish's World Wide Stout.