I currently have the same stem as you. I want to go threadless because the nitto does not have a removeable faceplate, which is an immense inconvenience. Also, I have heard people say that their front end felt a lot tighter/sturdier with a modern stem setup. My nitto stem is very creaky, and feels a bit bendy at times, since it's so long. And all quill stems that I can find with removeable faceplates are even uglier than I can imagine this zombie-like setup looking.