I've had the Oberwerk 11x56 and Oberwerk 15x70 (early version) and the Celestron 20x80. Based on those experiences and many others, as well as nearly everything that I've read or heard on the subject, I don't really think you're going to beat the new improved Oberwerk 15x70s until you spend substantially more than 5x-7x their asking price. By all accounts, they represent a sort of sweet spot merger that encompases good contrast, good clarity, reportedly much improved mechanics, and just generally the most bang for the buck. There are a lot of physical reasons why a 15-16x70 binocular will generally outperform models with slightly more or less magnification and/or aperature. Going to either a higher mag. or larger obj. means lots more attention has to be paid to eliminating chromatic aberation, and that, generally requires lots more money than simply doubling an already low figure. Also, from a strictly visual astronomical perspective, there's not terribly much difference between 15x and 20x, though there is a whopping big difference between 10x and 15x. To put it another way, 15x70 is the most major step up from 10x50, and the next step on the ladder really requires almost a doubling of either power or quality. And a doubling of quality from the Oberwerk 15x70s may well entail more than a quantum increase in price, not an incremental one such as a mere doubling or tripling. IOW, the next step up from them may well be something in the 25/40x100 range. Arguably, a really good, very high contrast smaller obj. bino with very good optics and slightly higher mag. would also be an option, but again, that raises the cash outlay to many times that of the Oberwerk 15x70s.
Obviously, I can't go too far commenting on what I haven't actually tried, so I'll suggest a different approach. Why don't you call or email Kevin Busarow himself and ask him your question straight out. Kevin is one of a very, very small group of folks in the astro biz that strikes me as a phenomenal straight shooter. I've had enough experience with a variety of other players in the astro world to say flat out that Kevin is one of the very few whose word on something I would take at literal face value. Phrase your questions well, and ask him straight out for his personal opinion. I bet he'll take the time to give a thoughtful and personalized response.