Dragging sidebar links worked fine for me all but once in Safari. Not sure how to tell whether it's actually being used, but I don't notice any problems.
[Edit: I was using a blocker that was blocking it. Now I've used it and can tell it's working, and I still don't notice any problems using it in Safari.]
[Edit: I was using a blocker that was blocking it. Now I've used it and can tell it's working, and I still don't notice any problems using it in Safari.]