FYI, I found the rear triangle flex with the CS-036 problematic at a riding weight of around 180. Any significant pedal torque would twist the linkage and cause the top of the rear wheel to offset a half-inch or more to the right. Chain rub was constant as a result. (I'm certain this is intrinsic to the model. I replaced and retorqued the chainstay, upper and lower bearings, and spacers, to no improvement.) Note also that the CS-036 and Workswell 108 are single-pivot designs, so they're best paired with a suspension lockout system if you intend to ride out of the saddle.
I would suggest buying a used Felt. You can find carbon versions, fully built with decent kit, for under 2K. You'll be out around $800 for a CS-036 frame, plus another $200 or $300 for a decent shock. The savings over a used rig are marginal and you won't get much warranty support from the Chinese vendors anyway. If you're really XC-oriented, I think Chinese hardtail frames are a considerably better value.