but it only helps in the very specific scenario of changing the order of a playlist with 100s of tracks in it. Are there enough people doing that on a regular basis to warrant the time to implement the other methods?
Forgive me, I wouldn't consider changing tracks around a playlist any more of a "very specific scenario" than doing many other operations that MB facilitates. Indeed, IMHO, as a music manager, dragging and rearranging playlist items with only 50 items is right up there with being a function in your face.
Fact is, you're the only one on this thread in the last 24 hours.
Conclusion, I dunno... this was +1'ed by 5 people, but hey, maybe you're right @Zak