I read some post on this forum stating that Matic-D has a different type or amount of FM. When I first bought my 99 Q45 it had slightly harsh shifting in 1st-2nd, 3rd-4th, 4th-TCC engagement. Fluid looked fresh, was at the correct level, and no foaming, so I figured it must have been cheap-o ATF from a 55 gallon drum at the quick-lube. I drained and refilled with CarQuest Dex/Merc which meets DexIII(H) which we use in all vehicles that require Dex/Merc. Noticeable difference in shift quality (better), but after about 100mi the smoothness was gone and it shifted the same as before, so I did three more D&Rs with the same result. Bought 12qts of Matic-D did two D&Rs and it shifts perfect and has been for about 3500mi. So at least for my Nissan "Any ole DexIII will work" is not true.
The Q has 73,000mls, I'm the second owner and no receipts for an ATF service.