For years Fleetguard held the edge on dirt holding capacity, filtration fine-ness capability and the ability to survive the Cummins engine . . . . very recently Baldwin has caught up as has Donaldson. Remember that there are only three or four filter manufacturers in the US. . . . . also the 6 cylinder Cummins puts out a vibration harmonic that will cause an improperly designed or manufacturer filter to self disintegrate. This was a real big problem on our 1st gens when they first came out in the late 80's / early 1990's.
Filtration techology has changed a lot in the past 10 years - mostly for the better! I have run Fleetguard and an occasional Baldwin ever since I have owned the truck - no problems noted - always good oil analysis results.