Windfury Totem is a flat Haste amount, so you'd be gaining 16% haste or 20% haste talented.

I just tried out the Stormstrike build and hated it, being close is bad for 2 things, first there is a noticable loss in DPS that was mentioned before and second your so close your pulling aggro non stop because your in melee range.
I'll be switching my spec back to what they had with a few variations.