Like everything in life there are disappointments and things do go wrong. The problems that it would appear SW have with QC are not what you would expect with a premium and costly item but s*** happens. It is how the manufacturer deals with the problem that becomes the key factor.It is so unfortunate you got a faulty Curio. It seems now Swarovski having quality control issues at least with Curio.
Strangely, I follow most of your ideas however, it seems not fair to compare the optics in Curio with Papilio. I had the Papilio for more than a year and got a Curio recently. I think the Curio is a wonderful little pair of binoculars that can compete even with full size binoculars. The performance of optics in Curio is phenomenal and lately I was thinking to sell my NL 8x42. Of course I see the magnification difference when compared both of them but I loose nothing when using Curios in real life. Strange enough when I use Curios I don’t wish for more magnification which I do when I use NL. I don’t know about the sample variations of Papilio, but my one dosent have that edge to edge clarity of Curio. Even the sharpness is far behind. I think you may get that stereoscopic view due to the edge fall off and lower magnification. When I use Papilio I always feel like watching the image from far behind but don’t get that feeling with Curios. Maybe our face types are too much different which make these different impressions about those binoculars. I think others also can add something for this comparison.
My recent experience with the manufacturer, and its lamentable (and ironically titled) After Sales Care, of the "Best Four By Four By Far' brings me out in a cold sweat.
I bought the Curio's based on the glowing review by the OP, (and others), and after physically testing them with my own hands and eyes. I thought they were superb and am delighted with them.
I do understand the OP's frustration and hope that mine continue to perform in one piece, especially after all the effort I took to smuggle them past my Beloved.
As for comparing them against the Papilio, I have the 8.5x21's and whilst they are lovely little bino's, especially at the close focus distances they were designed for, I do believe the Curio's to have more than an edge over them especially in my part of Mid-Wales where their water/weather resistance is oft tested.