Oh I have these too! Bought them from quettingen. Are yours also size 28? (edit, I see you mentioned it already :P)Superbia is my favorite cut all time. I try to get some more, there are some nice superbia's from this season.
They look much better in real, very well made wash. I ordered 28/30, they fit me perfect. The waist is like 29 in thavar 8x2.
The denim is 100% cotton, has a raw feeling to it, and it's thin but not sloppy! I can compare them to my 8NJ.
I ordered belther 816J just to check them out, and damn what a beautiful wash. I can't afford them for full price, but I will definitely buy them later. Btw in size 28W, the leg opening is ~17.5-17.8 cm.