Also, regarding the frog photos, they're really nothing that special; it just happened to be what I found to shoot that day, and so that is what I used as an example for the point I was making. The 173mm version is infinitesimally better than those taken at other focal lengths; the difference is something that would only be noticeable if one was comparing all of the images side-by-side on the same monitor at the same time. But those minute, almost-too-subtle-to-even-notice differences are important to me.
I will add the image to one of the galleries on my website sometime soon, and provide a link to it, if anyone is really interested in seeing it. But I promise you, it is just a simple image of a frog sittin' on a sun-bleached log with some blurred out mud, leaf debris, and spruce needles behind/under it.
Can we see the other ones at different focal lengths, too?