It sounds like you've had better luck with your trucks than I've had with mine. Mine has been a problem child on and off since it dropped a trans at 8,200 miles, (bone stock at the time). Not to derail, but just saying haha.
I've been changing my fuel filters every 15,000 miles, but I'll probably start changing them every 10,000 now. The set I changed out last night had 12,000 miles on them. They weren't "bad" by any means, but I could definitely tell the lower filter was plugged from bad/gelled fuel.
Getting back on track, I've never seen so much as a drop of water from the factory separator on mine. Even with fuel that I know was bad, the factory setup didn't catch a thing. I drained about a quart of fuel into a bottle last night, and there's no water at all. I left the sample in a bottle outside to see how it would respond to the cold, and it doesn't look pretty. It's -8 here now, and the fuel got pretty cloudy already; definitely not a good sign at all. Finding good fuel and/or an anti-gel that actually works has definitely been a challenge...
