Let me start by saying that I've historically gotten about 6000 miles out of a set of tires. That's held true for 3 previous bikes. It probably has something to do with the lo-o-o-o-o-ng gravel driveway at my house.
I've got 4700 miles on my original D407's. While both the front and rear tires have plenty of tread remaining, the front is cupping pretty badly at this point. At about 3000 miles, I started to notice a roar when leaning into a curve/corner. Now, I'm noticing the vibration that is coming from the front tire.
Dealer says they've not heard about this problem and it won't be replaced under warranty. So, I asked them to order a replacement tire. After 10 days, I was informed that the D408 is on indefinite backorder. Not something I wanted to hear given the state of the tire on the bike and my departure date for Sturgis coming up in a few weeks.
I mentioned my tire woes to a friend who rides a 2008 Yamaha RoadStar. It seems that Yamaha used a new Dunlop-designed tire on these bikes. Guess what?
Many RoadStar riders have reported that their front tire is cupping badly in the first 5000 miles!!!

Many in the RoadStar community -- including my friend -- are adopting the Avon Cobra AV71/2 with great success. Reports are the tires are quiet and long-lasting and they ride well.
Looks like I'm going to be buying a set of ME880's or AV71/2's for the SERG.