I think that the tests show that the ED version definitely captures more detail at both 22x and 68x, which you would expect when you consider that it costs more than twice as much than the standard version.
You can see from above that on both scopes, at 68x zoom when viewing the image at 100% size with no image manipulation, some detail is lost. The smallest of movements is greatly magnified, this vastly increases the risk of a blurred image. If you do use your scope at maximum zoom and want an image that you can be happy with, I would recommend reducing the picture in size in your image editing software then apply some doses of unsharp mask to improve the final image.
After my tests, my opinion is that a lower magnified subject will produce a sharper brighter image, there's also less risk of camera shake. Having said that, after taking successful images of the Great Tit at 68x, I will definitely use more zoom in the future if I think the situation needs it. It's nice to know you have the flexibility that a zoom lens offers.