For what it's worth...
I used to run the DCIII's and had great success with them. I can run low 23's and 22's at Summit Main consistently on a set on my bike. I would get at least 2 full days then flip and another 2 days out of the rear tire. I ran a front for 11 days... and then changed only because I had purchased a second front that was just sitting there. That is an insane amount of time to get out of a set of tires, considering the aptitude of my machine.
I then switched to a Diablo Super Corsa pro rear, keeping the DCIII front. I could get about 2 days then flip and another day at Summit Main for the SC pro rear. Not great wear, but I did manage to get into the low 20's (20.07 to be precise) on the SC pro rear. Big confidence boost for me.
I am currently running a set of Dunlop Qualifiers (209) and I have to say I do not like them. These are not Q2's, NTEC's, 211's or the 209 GPA's. I am sure that those tires would be better performing than what I have experienced on the set that I currently have. The Qualifiers that I am running show very little wear and stand up to the abuse that I put to rear tires, but at a significant sacrifice of rear grip. I find that the bike moves, a lot. It's not unmanageable, but I do not have the grip of a set of DCIII's. They will last me a bunch of track days though. If you want to run a conservative pace, a 25 or higher on Summit Main then the Qualifiers will work great, a better pace and you are probably going to want a set of 209GPA's. Which should be good to a high teens pace.
As noted above the Dragon Super Corsa, not to be confused with the SC pro's referenced above as that was a Diablo Super Corsa, are the newer and supposedly better than the DCIII's. I say supposedly as I do not have any experience with them.
From a cost perspective, if you can run a 190 on the rear, buy the 3 tire deal (209gpa's)from trackdaystore.com. Unless you are really moving out there, top 2% of A group, you don't really need a stickier tire, that frankly wont last as long.
Myself, since I can't run a 190 rear, I will probably stick to the Pirelli, whether it be the DCIII or the newer Dragon Super Corsa, I am not sure.
If this post doesn't make sense, chalk it up to the alcohol as I am on vacation
Kevin