Ha ha, funny how we can all be in agreeance, but still find some aspect to bicker over. Smoking meat is a long slow process, but you are supposed to keep adding water to make steam while it cooks. I'll wager that the steam makes more a difference on the moisture of the meat over fat drippings. But yeh, putting it fat side up in a smoker seems to be the choice that makes the most sense... except removing the fat altogether.... that makes sense also, and sounds healthier.
Also, fat could hinder the absorption of the smoke. Not speaking as an expert, just a dabbler in the smokey arts.
Good points.
Here is something I found on the web to explain why removing the fat on a brisket is needed
The brisket muscles include the superficial and deep
pectorals. As cattle do not have collar bones, these muscles support about 60% of the body weight of standing/moving cattle. This requires a significant amount of connective tissue, so the resulting meat must be cooked correctly to tenderize the connective tissue.
In other words, this is a working muscle. Another piece I found...
When we
exercise the tissues
release toxic materials and if these accumulate then we feel poorly.
So, fat that is adjacent to working muscles absorb these "toxins", this is why fat around a brisket has a much different consistency than fat around a ribeye, for instance (ribeye fat is more 'solid' for lack of a better term).
That said, keep about 1/4" or less of fat and keeping the fat side up when cooking is okay because it will keep that outer layer moist, but it's not enough fat to actually soak into the meat.
Again, the brisket cut has enough connective tissue in it to break down and give the meat a good flavor.
All of my experience comes from when I spent some time in Lubbock TX which is arguably the brisket/beef capital of the US (next to Kansas City probably). I was there doing field work on experimental crops and was in daily contact with cattle farmers...they know how to cook brisket for sure.