A whisker biscuit with straight fletching isn't terrible, but add a heavy helical and you are moving a lot more bristles than with the straight fletch. More bristles moving makes more noise, but I honestly don't consider the WB to be a very quiet rest, but that is only my opinion.
Of the others on the market, the Vapor Trail Gen 7 rests have always been what I considered decently quiet, but they all make some amount of noise, some being sharper then others, some being more dull or thunkish.
Which is the most quiet? That's hard to say for me.