Duncan Designed are good quality pickups. Not USA level, but certainly top o' the heap as far as low-cost import/stock pickups go. Part of that comes from the level of quality control SD demands (and pays for), even from their budget line. An HB-102 is not as dynamic and brilliant as a proper JB. But it's 90% there at a fraction of the cost and made from very good quality components.
Almost all overseas pickup manufacturers have a range of quality available...pay more, get more. Usually there's a standard production catalog for budget-seekers and that's where you get a lot of the rebrands like Dragonfire, TNT, GuitarHeads, etc.
But, resellers and manufacturers can often spec whatever they want if they're willing to pay a little more. That's where you end up with GFS, Tonerider, Tesla, etc. Some mfrs, using Artec as an example, also offer in-house premium brands like "Giovanni" and their "Milestone" stuff, which is on-par with SD stuff for the most part.
There has been a HUGE jump in the quality of import pickups over the past decade or so. It's a great time to be alive...good sound is inexpensive!
EDIT: But my money is still on the USA brands as far as innovation and artist support goes