Ibex makes lovely stuff, really top-flight. As to which is "better" there's limitless debate. Many, but not all synthetics transport sweat better and dry faster than wool. Wool tends to not stink after a few days while some synthetics acquire an aroma that can't adequately be described. Also, there's how well top layers glide over the base layer and how they feel against the skin and how they feel when you're overheating (e.g., climbing a steep hill in full sunlight).

No wrong answers, really, it's more a matter of preference as eithr adds needed warmth. It's what they do when pressed to the limits that separates them.