Almost 5000 miles on them in less than two weeks and still liking them a lot. Mostly riding the slab with a few curvy roads, a little wet and a couple of very cold mornings with no adverse drama. Visible wear, of course, but seem to have a long way to go. Wear is uniform - rear is flat-spotting a bit as a natural consequence of the slab-riding. No significant trapezoidal wear of the front which is so typical of the Michelins. I will be happy if I can get anything north of 10,000 miles on them. If I don't run into problems, they will be the next ones I buy (I have a set of T-30's to use up first). As I mentioned above, the RSIII seem to provide a very smooth and confidence-inspiring ride compared to most other tires.
I ran quite a few sets of Michelin PR2 and one set of PR3. (Never tried the 4's) Never felt that the Michelin tires were worth the "premium" pricing - not bad to start but always seemed to go downhill fast in terms of performance and noise. Sometimes could hardly wait for them to wear out so I could replace them. Same with the Pirelli Angel GT's (nice initially but impression didn't last). My less-than-stellar experience with the RS II (6 or 7 years ago) made me reluctant to try Dunlop's new offering but this thread was positive and the rebate pushed me over the edge.