The new CJ-4 additive chemistry is superior to the older CI-4 spec in terms of minimizing wear, oil consumption and engine deposits.
The one drawback to using CJ-4 is that the reduced additive levels necessary to meet the chemical limits of this spec means these new oils will not last as long in service. The estimate I've seen is that you can expect a reduction of 20%-25% in service intervals - if you run your oil out to the absolute limit using oil analysis.
I'd run a comparison test of the Duron 5w-40 to their new Duron E, 10w-40 over a 16,000km-20,000km service interval and see how the numbers compare. I think you'll be surprised at how well the new stuff does in terms of TBN retention...