An exception (large complicated Rc-trees) is the rope in xi-editor. If you load a very large file, the operation of letting go of the last reference is potentially a large enough pause to have an effect on UI responsiveness. I've considered adding a mechanism that moves the object into a deallocation thread (or a deallocation task running in a thread pool) for this reason, although I'm not sure how important it is in the grand scheme of things.

In a GC'ed language such as Go, this would not be a problem. The flip-side is that I can safely and efficiently do updates in place, because Rust's reference counted type has a way to determine when you're holding the only reference.