i'm almost 100% sure we did the numbers on the two enchants 5 or 6 months ago, but i can't find the thread.
i may be off, but i think that just the static numbers on a 2.4 speed weapon had agility beating haste in dps by like 9-10 damage per minute ... it wasn't huge ... and i'm thinking we didn't compare those numbers with a PPM enchant in which case, i'd bet that haste would come out on top.
all i know is i switched a few months back for certain fights, but can't at this time remember why.
when i hit the office this afternoon i'll try and find those numbers, if not, i'll just redo them