Rob -
I hear what you are saying about the 5.5" shields. That's what I mainly use now. These are the 4 fletch I've been shooting.
They measure 4.5" and are the same profile as my 5.5" hi-pro shields. They are 60/64 Douglas Fir with 160 gr. points. Although they are much heavier in weight and hit lower at 20 yards, from what I see, they fly as good (consistent) as my 55/59 gr. cedars with the 5.5" hi-pro shields.
That said, the 5.5" shields are white and I actually see (they are spinning like a top) those much better in flight than the yellow w/ white nock.