I love that beer - bought it in London the first time, and to my great pleasure it was available in Norway for one or two Christmas seasons, then it disappeared from the market here. Glad that it still is being brewed, though.
I have had a few others on the list, but Twelve Days is the only one that made a lasting impression on me.It is not extreme in any way, but nice and well balanced.
A decent Christmas / Yule / Winter beer (ales as well as dark lagers) should be between 5.5% and 8%, in my humble opinion - with a few stronger Belgians added.