Sean, my impression of the 12 X 36 IS is totally positive. I too am (or at least *was*) sure I could hold lower mag binocs steady, although in my case the lower mags are 8Xs, not 10X. The much higher mag IS binocs made it clear to me that what I thought was "holding steady" really wasn't. This realization hit me the first night, when I could see two sets of doubles with the IS that I couldn't see with the 8xs. The difficulty with the 8xs wasn't that the doubles were too tight (although tight they were), but that tiny hand motion subtly jiggled and smeared the image, just enough. (I can't be totally sure of this without trying the same view with 8X IS, but I don't have any. I'm reasonably certain, however.)
My pair is well-corrected to the edge. Honestly, I haven't looked through them critically to determine what percentage of the total FOV is degraded; I simply haven't noticed any such problem. Also I've used them during the day for some casual birdwatching. At the percussion retreat 3 weekends ago I went down to the dock and checked out swimming birds at various distances. I was really amazed to recognize a pair of mystery ducks' yellow eyes at a range of ~ 175 yd., which allowed me to later identify the pair as Barrow's Goldeneyes.
I chose my binocs after receiving feedback in a post here
, which might be a place to start. Note the reference in it to Gary Seronik's IS comparisons on his website. I decided I wouldn't spend $1200 for the pair I really lusted after, but I'm very happy with what I bought for about half the price.