Why do people keep asking about stat weights when there is a whole thread & spreadsheet dedicated to that :P
http://www.mmo-champion.com/threads/...at-Weights-7-0
https://docs.google.com/spreadsheets...#gid=0&vpid=A1
Since I don't think anyone has calculated the value of haste breakpoints, any talk about the breakpoints is probably just guessing, but I'd wager only Mana Tea and EF Mastery procs are the only significant ones, unless I'm forgetting something. So get those if you're close to them. Otherwise, Haste is kind of awful.