Around the farm, we use Rotella in every diesel we own honestly. In fact, our John Deere 2420 swather just had a major overhaul done about a month ago. Just shy of 11,000 hours on it before a coolant sleeve seal gave out in #3. It still ran like a champ when it was pulled to be rebuilt though!
After the rebuild, we broke it in and changed filters before I swathed with it for a couple of weeks. It has yet to use a drop of oil nor has it even started to discolor yet. Clean as the day we poured it in the case.
As far as trucks, both the PSD and IDI get the same oil and FL1995 filters. When I changed the PSD oil yesterday, the oil was just starting to turn dark. Never used a drop.
The IDI however is another story. Ever since I had a friend's shop replace my valve seals, I have had to add at least a quart between oil changes. Although, it still turned the oil black within a day even before the seals were ever touched. Not the truck's fault though really on that front. Unfortunately, it has to wait until all of our hay is off the ground before I can crawl back under the hood...
On the front of improved filtration, I have heard quite a bit of praise about Fleetguard filters. Especially this one for IDI and PSDs alike:
http://www.dieselmanor.com/fleetguard/LF3974.asp
I can't find much information online other than rumors, but I'm told you can call their hotline for the filter specifications. I may be looking into that unless I can continue to get the FL1995 for under $10...