More good questions.
I'd say that over the broad span of their offerings, Donaldson is out in front by a decent edge. No filter manufacture commands any lead in all sectors of all markets.
Many decisions on a filter supplier selection on a fleet basis aren't based on ultimate performance ..nor on costs (per se~) but how the supplier can fit the needs of the customer. I learned this from a supplier to the school bus parts trade. The quality of the tail pipe wasn't as important as how fast I could get a replacement due to the driver backing into something on a weekly basis.
..but as far as Donaldson being ahead, as I've said, depends on what you're looking for. For passenger cars ..I think that they "also ran". On heavy duty, they've got a premier line with the Endurance line. Hard to top. In bypass filtration, I'd say that L-F has a great product if you're an OTR type...as does a number of manufacturers ..including Amsoil.
So what are you looking for in particular?