Another TMC member, who lives near me and has a lot more experience with performance driving, has put the DZ101s on both front and rear. I considered it because they're so affordable and actually on special at TireRack (I think it was $83 per front and $95 per rear) but my reduce/reuse/recycle mentality stopped me wasting the rubber on the still-good fronts. I'll ask this other driver if he has any special comments about the tires with all four new ones.
Also - not sure if this means anything - I compared the tread patterns on the rear DZ101s and the front AD07s and they are very similar indeed. I actually took a photo to post here, but lost it [trying to transfer photos via bluetooth to a non-existent directory on my laptop, oops]. Next time I feel like taking the wheels off, which I have to do for a different reason anyway, I will take another picture. Hopefully before I've completely balded these rears.