Yeah, I have. Everyone keeps talking about the higher viscosity fluid for the 2006 and above. I will also ask the transmission rebuilder what they recommend.Jax,
Do some research on transmission oils. I have read that the Fords recommendation of using ATF in the ZF6 (and ZF5) may not be the best choice. RoadRanger recommends a synthetic mineral oil (PS-386) for their transmissions that I would actually be tempted to use in the ZF5 if had I kept that transmission. The RR stuff is pricey stuff for sure. I'll take a pic of the jug I have this evening and post it.
All-in-all, I am pleased with what I have found in the truck.