Even if someone says they do, I don't believe it. As someone who runs -CURRENT on vm's and physical hardware, it's not stable to do anything aside from development and testing on it, and it's not meant to be stable as well on purpose.

Unless Netflix enjoys filesystem wipes, file corruptions, and extremely reduced performance due to kernel level debugging flags that are enabled by default (and often can't be disabled due to ongoing development efforts), then they are not running -CURRENT. Remember, -CURRENT runs slowly because of debugging code!!