The fibermesh hairs are becoming more widespread, I guess because people's systems are becoming more able to handle the resourse requirements, RAM.

I only have the Desir Hair and it's pretty cool, and doesn't take that much longer to render than transmapped on my system. It's quite complex - composed of 8 parts, each part morph independently, and a micro part (a thinner layer of hair on top of the main hair). Some of these hairs look a bit clumpy/dirty but others look great.