I just changed the original Donaldson on my 6.0 PSD (2004). 95k miles, the indicator hadn't moved. Filter still looked good on the back side, with no dirt upstream of the filter.
This is one a customer had us change because it was 6 years old and there was no restriction. It really could have stayed a lot longer, but I cut it open to see how it was made and how much corrugated fluting there was. Those things hold 3.5 lbs of dirt.