I'm not an expert in this area (or any other, for that matter) but, my take on the CJ-4, CI-4+ controversy is that the new CJ-4 does not have the strong additive package to handle the byproducts from LSD fuel. The CI-4+ was LOADED with a strong additive package to handle the sulphur & resulting byproducts from the combustion event.
My thinking is that if you are running ULSD & using the CJ-4, you probably are going to have a good experience with it. However, if you are still running LSD, the CJ-4 probably will not work as long as the old CI-4+. If running the LSD, it may be a good idea to change the oil at 5000 mile intervals. You may not want to try extended oil drain intervals.
The base oils in the new CJ-4 is supposed to be stronger than the older CI-4+.
Hope this helps.
Joe F. (Buffalo)