The Diamond Back radials on my car are about 8 years old and still look good. No separation of the whitewall and wear is fine although they only have about 12k miles on them. Ride and handling is great. Very happy with mine.
Think you were going with new wheels so won't apply but the only problem I have with mine is that the whitewalls absorb rust from the wheels after a few times washing the car. I should have had the wheels powder coated rather than painted. Been using Castor Oil Superclean on the whitewalls as recommended by Diamond Back - works fine and doesn't seem to have had any effect on the tires.
If I remember correctly the warranty states that they must be hand mounted on the whitewall side - may have changed - but if you've ever seen how the machines stretch the tire over the rim it's probably not a bad idea. The fellow that did mine hand mounted the whitewall side then flipped the wheel over and used the machine on the non-whitewall side.
The shipper actually ran over 2 of my tires with a truck or forklift - pretty obvious tracks across them. Called DB and they shipped out 2 new ones the same day and an RMA sticker for the damaged tires. Didn't have to hassle with taking them in and trying to explain the problem to the shipper. Great customer service goes a long way.
Hope ole' pinky is getting better.....