Well, nobody has answered, lemme bump this one a bit. I have not used it for competition BBQ, but, I have smoked ribs and shoulder from both Berkshire Black and Berkshire/Duroc crosses and you will not find a tastier pork meat. It does have more fat in some parts of the carcass, it was trimmed from the shoulders I bought. There did not seem to be additional fat apparent on the ribs other than at the chine(?) bone. The ribs do smoke up beautifully and both apple and pecan woods complemented the pork nicely.
In terms of timing, I found it cooked at about the same rate as commodity pork, resulted in the same basic texture once pulled. The ribs were similar in texture (I smoke with no foil). In general the shoulders rendered a lot of fat, so you will want a drip pan. There were some 'issues' between BIL and I, something about me 'cooking and running', i have no idea...
The flavor is what keeps me paying more for the pork than commodity pork, it has a more porky flavor and the fat is very flavorful. The texture is very similar to commodity pork, however, I find that Berkshire hog pork is a little more moist cooked to the same level of doneness. In an unfortunate blind taste test, I found that people (family) can tell the difference between the two types of pork once pulled.
I have also grilled the chops, tenderloins and sirloins and found them to be a little more fatty and marbled than commodity hogs, but not in a bad way. The pork bellies are incredible, again, not competition meat, but if you find some it is worth the bacon, if you will.