Roasted coffee age and storage aside (let's assume 7 days off roast, packed in paper bags), and roast profile aside (assume for a moment that we're taking about a "good" espresso roast profile on any particular roaster)...
Does the consistency of crema (i.e. tight bubbles vs. wide) correlate to the style of roaster that the coffee was roasted on? For example high air-flow drum roasters vs. lower air-flow drum roasters. Fluid bed vs. drum? Highly insulated vs. low insulation? We might as well use brands here: Diedrich vs. Probat vs. Loring vs. Renegade vs. Sivitz vs. etc. For those using "control-able" roasters (i.e. air flow can be controlled) what do you find?
I guess I'm really taking about the affect of convection vs. conduction vs. radiant heat?