I don't have a problem with it. Call it character. Adds some interest. However when I see these sorts of "interesting" imperfections (basically tree branches) I think, hmmm... is that going to be a potentially weak spot in the wood that is going to cause problems down the line? As far this example goes I say no and it looks great, but one does start to think about "old twisty". I think each knot like this has to be judged on its own merits. A big manufacturer would probably reject such a neck which is why all their instruments look all the same and are so boring. This is where imperfections mark the exceptional, hand built instruments. These are not products, these are works of art. Each one is an individual and not just another number in a long line of serial numbers. This is an advantage.