I've used turbinado when I was out of regular, and I didn't really see a ton of difference, but my roadside never gets too terribly dark. I do it indirect, but right up next to the coals, just not right over the top of them. If you control your distance from the coals, you can still get that amazing roadside crust and color, but without the real dark sugar. I usually to big bone-in breasts as well, and the marinade is fine, they just need alittle more time. A thigh after ~4-6 hours has great flavor, but a bread will take 12 hours easily, even over night, and not get over-marinated. With the turbinado, since it is a little more granular and large, you may want to heat your marinade to disolve it some before basting.