Waking this old thread up. I'm also consider a FS Carbon 27.5-frame for my XC Race. Only 100mm travel today, and could easy rebuild my Reba to 120mm. But that's it. I don't need more.
Have also checked out the CS-156, but have no idea what they cost?
I have today a good HT that I like a lot. But I consider to swap the frame for a either CF-HT or even better, a CF-FS. My concern is how to know what quality one get buying a no name frame.