At the risk of beating on an inane topic, my beef is with the lack of a horizontal 'slide' piece on the existing shade, to allow for extending the visor to a wider shade...
My complaint on these cheapazz visors is not based on vertical coverage, or sunlight creeping in over the top/bottom of the existing visor.
But, I bought some Geezer sun glasses this past winter in FL: the kind that go over my regular eyeglasses, and that has reduced the problem...I look like MrFookinMagoo, but vanity at nearly 67 Yrs old, is not a priority.
GL, mD