I know a few gen 2s that run them and love them. They tend to be along the pricier lines, so less people get them.
Sorry I am not more helpful than that. I was considering these before I went with the (used) SAWs and it looked like the cheapest I could find them at wholesale was around $850. But I hear the customer service (to rebuild, etc) is fairly decent, too.
My List
1) Saw - closet to king but king is way overkill for anything an xterra will ever touch
2) Icons- from my research they outlast rads but dont come close to saws when performance is in mind, these are durable great lasting coilovers.
3) Radflo- love mine but ive already gone through two lower ball joints and the seals are said to leak easily.