With regard to the choice between a close-focusing 8x32 and the Pentax Papilio (as brought up by Alan), I find the image quality and comfort of use at distances under 8 feet or so to be much better with the Papilio than with my Eagle Optics 8x32 Platinum Ranger (which focus to under 3.5 feet), Zeiss 8x32 FL (which focus to 5 feet), or Bausch & Lomb 8x42 Elite (older style, which focus to 4.5 feet). That said, with some adjustment of the interpulillary distance, the Zeiss and B&L are quite good at their closest focus. I don't like the EO Rangers despite their excellent close focus--their image quality outside the center of the field is so lacking that at close distances (in which case only the inner edge portions of the left and right fields overlap), the binocular image is not easy on the eyes, and I would have the same concern with the Minox 8x32.
What is there to look at with the Papilio at 20, or, for me, 18 inches? All sorts of things of course, but I admit that it is a very different universe than the domain of traditional binoculars. The Papilio is almost a categorically new device that meets a different set of needs when used at its closest focus distance--it is a sort of long-distance, binocular loupe. When it comes to butterflies, its great innovation isn't so much the 18 inch close focus, but the very comfortable 6, 5, 4, 3 etc foot close focus operation. Many hairstreaks and small skippers are difficult to identify with certainty or to appreciate fully with binoculars at 6 feet. I find that when I have found such a butterfly and I am carrying binos that can only focus down to 6 feet that I want a closer view/larger image (even if I can make the ID at 6 feet), which necessitates getting MUCH closer (a foot or less away) using my naked eyes before the image is superior to what I achieved using the binos at 6 feet. I other words, there is no payoff in terms of a better view of approaching a butterfly to closer than 6 feet until I am approaching the close-focusing limit of my eyes. Since many butterflies can be approached easily to within 6, 5, 4, 3 feet, it is annoying to have them fly off before I have successfully approached to 1 foot, at which point I might have had a better look. With the Papilio, one doesn't have to set down the binoculars to attempt the super-close approach, and at distances of 2-4 feet (which many butterflies tolerate), it offers a view that can only be matched by looking at a captured/pinned butterfly with a hand lens.
Since this is a birding discussion group, let me add that I much prefer full and 2/3 size binos for birding and other demanding viewing at moderate to great distances, so for combination serious birding with serious butterflying, I would choose the Zeiss 8x32 FL over the Papilio, or I would use a full size binocular and carry the Papilio without its strap in a case on my belt (One nice feature of the Papilio is that the neckstrap can be removed/attached in a few seconds).
--AP
P.S. With respect to the Papilio's focus knob, yes, it does make 3 complete revolutions between 18 inch and infinity focus, but it is a small circumference knob which operates very smoothly (yet with no play), so I can spin it quite quickly with my first or second finger. I find focusing from one focus limit to the other to be faster and less aggravating than I do with my (old focus ratio) Swarovski 8.5x42 EL (with 7 foot close focus).