I prefer fine ground spices for everything but Black Pepper on traditional Barbecue Meats using a traditional type of rub. Granulated spices can get a little gritty in texture. IMO the bark should be a caramelized layer of meat and spice not a caramelized layer of spice like you sometimes see. A fine grind will sort of seep in but coarser spices will sit on top.
However there are lots of great ethnic variations you can do with coarser grinds of Cumin, pepper flakes, coriander and such.
Spicewine Custom Medium Large (Thank You Sawdustguy)
Primo Oval (and BBQ Guru for when I need a nap)
ECBrinkmann Vertical Smoker w/mod charcoal pan and thermometer (used mainly for storage)
Meco Aussie Walk-About (AKA the princess grill)
Klose 20x30 Smoker (sold)
Thermos Square Grill (abandoned at Giants stadium)
Kenmore/Charbroil Gasser got dragged to the curb