It is much more actively maintained than Kilim, more general, and has better performance to boot. Also, Quasar fibers interoperate very nicely with plain threads. Blocking operations (such as channel receive) block the thread if you're running in a plain thread, and the fiber if you're running in a fiber.
In fact, we've even had time-sliced preemptive scheduling, which we've taken out because it didn't give performance benefits to fibers that block a lot, and for computations that don't, there's full blown threads (which Go doesn't have).
