I saw them in only two places that I can remember - the 2012 HofC Highland Collection Catalog, and I'm pretty sure Matt posted some pictures of them when they were first marketed. Also, they were made to order and relatively expensive. That's probably why they didn't "take off".
Last year I bought a pair of the Highfell Marl and Scotspine Marl and they are very plush (GORGEOUS! as Artificer states), significantly more than the other very fine HofC lines, eg. Lewis. I've received complimentary comments and questions like, "Did you hand knit those?". Of course I say "yes", they look at me adimiringly, and then I confess. 
The downside (if there is one) to me is they are VERY warm, so I only wear them in cool/cold weather, which fortunately, we often have in the mountains.
I changed my signature. The old one was too ridiculous.
ith:
Bookmarks