I don't know if you are asking about the older ELs w/ Swarobright coatings or the brand new "Swarovision" ELs. Swarobright is Swarovski's marketing name for dielectric prism coatings. Dielectric coatings primarily decrease the amount of light that is lost bouncing off the mirrored surface of the prism, which leads to a brighter image. The Swarovision is a totally new design that incorporates ED glass objectives. They also have a super-low distortion view. This can be a problem for hunters, however, because a lack of pincushion distortion can cause the image to appear like a "rolling ball" when panning. The rolling ball effect is annoying to me, so I prefer a little pincushion distortion, which the older ELs and SLCs had. The amount of distortion in a binocular is not a flaw, but is intentionally designed into the binocular. Some people do not notice the rolling ball effect, and love the new Swarovision. It has very sharp edges.
Hope that helps.