What I'm talking about here is nickel covers that do not cover the whole top of the pickup, such as Gibson P-94, GFS Dream 90/Surf 90's, etc. Do these offer much in the way of noise rejection, or are they primarily for aesthetics? I imagine they are somewhat similar in function to the foil-wrap that some of my HB's coil windings have. Do these pickups look bad w/o the half-cover?