I don't personally think it matters much, but I have started doing them fat cap down after reading here about the whole "heat shield" thing. Seems logical to me and after thinking about it I don't really see much benefit to the whole "basting" idea which is why I started with fat cap up.
18.5", 22.5" OTS
Large BGE (chambersuac's)
The Fiery Furnace (chambersuac's)
Big JT's Smokin' BBQ Competition Team