No no no, you've forgotten a very important category: FOCUS CONTROL. The Swarovski EL SV have decent close focus for butterflying and the like, but it is nearly unusable because it is so _terribly slow_ to adjust. If the ratio were increased, we would lose precise focus at distance, which wouldn't be good for birding. The solution is variable-ratio focus. For those of us who regularly use bins for close viewing, and especially for those of us who are constantly switching from 5 feet to infinity, variable-ratio focus would be a SIGNIFICANT IMPROVEMENT. Why do so few bins (e.g. Pentax Papilio, discontinued Brunton Epoch, discontinued Minox HG) make use of it? I think it is silly to give a bin excellent close-focus spec (as many modern bins do) and not also give it the focus control needed to make use of that capability. This is low-hanging fruit, easily achieved with existing technology.
--AP