I don't know, is it though? Properly done reference counting AFAIK requires using atomic increase/decrease in order to be safe, and that creates a bit of overhead every time you assign a reference, while assignment to a reference with a precise GC is basically a pointer assignment. It's much better for latency though, given that the overhead from rc is deterministic. It has been a few years though since I've looked into garbage collection techniques, so I could be a bit rusty about the current state of the art.