I'm not sure why having a few less pieces with haste is a bad thing, with high ilvls on gear won't haste and mastery swap in priority at some relatively easily reachable intersect point? (not to mention the set bonus push us closer to being gcd capped than currently....maybe dunno how it compares to extra RP)
Before they changed our tier, there was overall, less haste in this tier than there was in T12, and if i'm not mistaken, there was more haste in T11 than T12.