At one point, in about 2008, I had an 804, and both the ED and non ED 820 binoculars. The ED 820 was supposed to be ED, but it came with the yellow Swift logo. The ED version was supposed to have a red logo button. I think that was the first year the ED version was available. When I asked I was told there was a foul up in the factory and the gold logo was used instead of the red. I had them send me a non ED version. That led me to believe either one of two things was true. First there was no observable difference in the two. Second, and what I tend to think,is that the logo switch was a tall tale.
I did not keep either of the two 820 binoculars. The 804 was every bit as good, and the diameter of the ocular assemblies of the 820 were too large to be comfortable for me. I do not have particularly deep set eyes either.
I note the current photos of the 820 ED and 820 T show a binocular with obvious physical differences to the ones I had, which were like the ones pictured in the Amazon link. Just be aware that the Swift of today is not the Swift of Humphrey Swift. Don't know if I could bring myself to buy one from this outfit at the price they list.