I'm the guy that started out touting the DLX on this forum. Let me say a couple of things.
First, the DLX is a great machine. I just made 13 pizza doughs in a batch, thats over 9 lbs of dough and it turned out great. For the price ($460) you can't beat it for making large batches and it's a sturdy machine that makes GREAT dough.
Second, I bought the DLX after a lot of frustration with the Kitchen Aid which can't handle tough work. However, I've since learned better mixing techniques. The dough itself is better if it's not tough, so this means the KA can in fact make a good dough. The key is learning more about autolyze and mixing at high hydrations, which I discuss at length on my site. If you let the flour and water soak for 20 minutes prior to mixing AND do most of the mixing with very wet dough (halfway between batter and dough), you can make an excellent dough and it doesn't tax the mixer that much, even with high gluten flour. I've made up to 4 doughs in a 4.5 quart KA mixer and they were great. The motor did not break a sweat because the dough was wet and soft - so wet that the hook goes through the dough and the dough releases if you lift the hook. Only at the very last minute is a little more flour added to lower the hydration just a bit. The larger KA can probably make a bit more. You obviously can't do a large batch like with the DLX, though.
The DLX is the better machine, I don't think that can be disputed. But it's not a pretty machine like the KA, it's bulky and since most people have a KA, I think they can learn to use it.
Bottom line, learn better technique and you will stop hating the KA as much. But if you want a great machine to make large batches the DLX is a great choice.