I've purchased my fair share of BB nibs and while other companies can produce BB in Gold, the steel BBs have always been a disappointment.
I've received a few(five, from two different orders) nibs from Osprey and they have all out preformed every single steel BB from other manufactures. Flow has been significantly better and the line width on the page is actually what I would call a real BB.
I always think that line width is king, but comparing Osprey nibs to the other steel BBs I realize flow makes a significant difference to how good I feel about the nib. A wider line that does not have enough flow can make a lovely black look grey and cheap.
My last and probably most important point in this is QC, I don't know if the manufacturing process is just better or if they get tuned but I have yet to see the tipping/slitting issues from "luxury" manufacturers. I've dropped $300+ on a nib that required rework and tuning multiple times. That hasn't been a problem I've run into with these BB from Osprey.