It's the "switchback" weave. Similar to "boiled wool". I happen to really like the waffle-y switchback weave feel- but then I always a soft thin base layer under it. The other Ibex wool weaves are different and not nubbly at all.
I saw the Ibex LongTrail sweater at a store this weekend. It was soft and tight weave- very elegant and smooth and thick. Nice! But I didn't need any more sweaters. The green one was a pretty & subtle cool beige/green.