I know what you mean. I have the Canon 10x30 IS II, 12x36 IS III, 8x20 IS and 10x20 IS. I recently tried the Canon 8x20 IS and 10x20 IS in my search for lighter binoculars under 20 oz. because of arthritis in my shoulder. I could see more with the Canon 8x20 IS than I could with my Swarovski NL 8x32 or 10x42 NL. I always test my binoculars for resolution by reading some lettering on an A/C unit on top of a building about 200 yards away, and I could not easily read it with either $2500 dollar NL's, but I could read the lettering easily with the $500 Canon 8x20 IS. I can see more detail on the bird with the Canon 8x20 IS than the NL 8x32 due to the IS and both the 8x20 IS and 10x20 IS handle glare better than either NL. If you put the NL on a tripod, it would beat the 8x20 IS for quality of view by a very small margin because of the bigger FOV and slightly sharper edges, but who does that when you are birding and moving around? By the time you get the tripod set up, the bird would be in the next county!
The Canon 8x20 IS and 10x20 are both surprisingly good binoculars for $500. The 10x20 IS doesn't have as big of FOV, and it is not as bright in low light as the 10x30 IS II, but I think the optics are a tad better with slightly sharper edges and both the 8x20 IS and 10x20 IS handle glare better than the 10x30 IS II I think because the objective lenses are more inset. Both the 8x20 IS and 10x20 IS are for some reason a little steadier than the 10x30 IS also with the IS on and once you engage the IS it stays on for 5 minutes. The Canon 8x20 IS and 10x20 IS are optically better than any pocket or compact binocular I have ever tried, including the Leica Trinovid 8x20, Swarovski CL-P 8x25 and Zeiss Victory 8x25 probably due to the big advantage of the IS and being a porro I also notice some of the porro stereoscopic image even though their objectives do not have a lot of separation.
I have never had a 20 mm aperture binocular that wasn't finicky for eye placement, but the little Canon's are not finicky, even the 10x20 IS with only a 2 mm EP. I think it is because the IS keeps the image centered over your cornea with no movement, resulting in no blackouts. I usually would never recommend an 8x20 or 10x20 for birding, but I think if you bird mostly in the daytime where the smaller EP is not an issue for brightness either one could work quite well, and they only weigh 15 oz. and only cost $500. If you could have only one Canon for birding and you bird in daylight and low light, the Canon 10x30 IS II would still be more versatile because of the bigger EP and brighter view in low light than the 10x20 IS, and it is still pretty light at 21 oz.
I am realizing that IS is more important than all the other qualities of a binocular, and it puts them light years ahead of a traditional binocular if you want to see more. It is more important to have a steady view than all the fancy optics in the world. Swarovski, Zeiss and Leica are missing the boat, not developing an IS binocular. It would improve their view more than all their other optical advancements.
