With the new fuel injection systems, I'm thinking that keeping water out of the common rail (is this what Kubota uses?) would only help prolong pump and injector life. What aftermarket separators are you using and what is your opinion of them?
I use Dahl with a 2 micron element. I've had it on my L3000 since it was almost new and it works great. I purchased mine thru Amsoil but they can be bought thru any Baldwin dealer. I use the Dahl for my primary filter and it's so efficient it all but eliminates the need to change the factory filter. I remember reading about them before I bought mine. It said when using the 2 micron filter element it would eliminate fuel system wear. I fuel my equipment from the same bulk tanks and my L3000 is the only one that I never have fuel issues with.
I see some water when I change the filter but not a huge amount. But I have my own bulk tanks and have them set up with water drains on the lower ends and have filters on my pumps. My point is all my fuel is filtered before it goes in my equipment. My tank filters are 5 micron so I don't have or have never had much trouble with my filters getting plugged.