It is wonderful. I am also a fan of Yeti Imperial stout. They have an "Oak aged" version which would not sit well with purists. It is delicious at first sip, but you can't drink 2 of them!
I actually brewed a really good chocolate stout 6-7 months ago. I actually used (Germans cover your eyes) a couple of hershey's kisses in it! Very unorthodox, but it worked great.