There is no "one" answer to this question, imo.
Not every DiMarzio pup sounds bad, just as not every Duncan pup sounds bad. It's mostly a matter of personal preference.
Overall, I'm 10x more satisfied with my experience with BK than with Duncan, DiMarzio, Fralin, Barden, or EMG.
What I think makes BK pickups so great is the attention given to each one, as well as the quality of the parts. To say that Tim Mills and company are fanatical in their attention to detail is a gross understatement.
What makes BK, the company, superior is the amazing customer service, personalized attention, and absolute commitment to customer satisfaction.
I live in the US -- I can get Fralin, Barden, and Duncan custom pups much cheaper. Dimarzio is 15 minutes from my house with no traffic. I still choose Bareknuckle because they are just as committed to my tonal quest as I am. :)