It came out pretty good - I smoked it between 250-270 for ~2 hours until it reached 120 internal, then into the 400 deg oven until 135, then onto the counter until 145 at which point I sliced.
It did not have much marbling - you're correct - but it did have a fat cap - maybe 1/4 to 1/2 in. thick.
I used a salt, pepper, garlic and cinnamon rub - no burning at all
It was more tender than roast beefs I have eaten in the past (oven-cooked), but certainly not as tender as the 3 standing ribs I've done. Anyways, another win for the smoker ...