I tend to reorder a lot, particularly when creating "mood" or "greatest hits" playlists. Generally with the keyboard rather than the toolbar buttons, though. (I am trying to train myself to use the toolbar for quicker copy/paste, but as my colleagues will attest, I don't come from a GUI background and I tend to prefer typing to mousing.)
Anyway, the jump-to-top issue has been there since forever (like, JE 1.x), so it's definitely not a regression. Actually, I just assumed you were aware of it - assumptions are always dangerous things!
Thanks for your quick responses, too.