These new D-A pads do not melt when wet and do not become impregnated with tiny pieces of metal from the rim or debris from the road, unlike the previous version of D-A brake pads. I was always picking out stuff with an awl before and using fine grit sandpaper to finish the pad surface - no more. The new pads, coupled with the DA 9000 brake mechanisms result in much better stopping power whether wet or dry. I ordered and extra set to retrofit a different bike with older D-A mechanisms.
These replaced the stock pads that came on my Specialized Allez. They fit perfectly into the stock shoe housings, but the new pads were noticeably better in both wet and dry. These were a good investment!
I have never been disappointed with a Shimano Dura Ace product.
The quality control is so good , I have never experienced any problems.
So, for me, the slight extra cost for Dura Ace is well worth it, and almost always less than the other high end groups available.
I don't experiment with other chains, brake pads, cassettes or anything aftermarket as I feel Shimano makes the Dura Ace parts to work together the best possible.