I have and use both a lot.
The Ibex woolies have cuffs, which make them seem more long-john like in style. They are longer in the torso.
The SW microweights are styled more like normal tops, and look more like a normal pullover and don't have as long a body length as the Ibex. Hence I like how they look over a skirt.
They are both about the same weight and warmth.
The SW ones are a bit more prone to holes, but their style is nicer to wear as a normal lightweight merino top. I wear the ibex woolies more like underlayers, and the SW ones more often as over tops.
Both are nice.
