Found a 9.5 lb Beef Knuckle at the local restaurant supplier and decided to try it. $2.65/lb was a nice price. Did some research here and on the web and most people seem to say that low and slow is the way to cook it and it can turn out like roast beef. Some use it as stew meat.
I decided to treat it like a brisket so I put it in my 055 at 225 for about 17 hours. Not exactly sure what temp it finished at because I was sleeping and it turned itself off at 3am, but it had reached 173 deg. about 4 hours prior to that and seemed to be just coming out of the plateau.
I had foiled it at 164 deg. along with a cup of beef broth to provide some moisture.
It turned out as a nice, huge, chunk of beef. My wife is marinading some of it for fajitas tonight and the rest will make sandwiches or whatever else. It is very tender and reasonably moist so it should go well in any dish where brisket would work. However, it is a lot leaner than the point of a brisket which is something that makes it more friendly to my wife. Haven't been able to cook a full packer for many years because she doesn't like the fat content.
I think this is something we will be doing again... because it is tasty and also a bargain.