Your question does not have a simple answer because optics, glass, optical coatings, binocular construction, etc are not simple.
If you took two otherwise identical binoculars, one with high quality ED glass and one without, the only difference that you would see would be that in certain light and viewing conditions the non-ED bino would have a colored fringe around everything in view while the non-Ed would not have this fringing and would appear sharper.
But, ED works only if the binoculars are properly designed and built to begin with and the ED glass is used in the design, not just slapped there. ED will not make a difference on your 1500 yards deer in the bush if, for example:
-you are looking against the light, the deer is in the shade, and the binos have poor baffles and lots of light dispersion
-you have handshakes (you WILL NOT see that deer at 15x and 1500 yards in the bush without a tripod or support of some sorts)
-many other reasons too numerous and technical to detail here (i have no clue).
In other words: if you purchase a decent glass, you will see your deer or not see it regardless of ED glass. In the past i have used similar optics (binoculars and spotting scopes) with and without ED, and the observable difference was a slightly sharper image with ED, but everything was there to see was still there even without ED.
It is the optical build that matters more than ED.
To give you an example: Between an ED Leupold spotting scope and a non ED older Swarovski scope, i always found the Swarovski better.