The Duncan Designed pups are built in Korea according to SD specs but using locally sourced materials for wire, etc. IMHO, they are better than the stock pups of some Korean made guitars. ESP for one is making some kick-a** guitars with Duncan Designed pups.
Here is what the Duncan site says about the Designed series and the HB104s you referenced.
"While USA-made Seymour Duncan and Basslines pickups are intended to fit on instruments with list prices over US$800, the Korean-built Duncan Designed pickups are intended for OEM use on guitars and basses with retail prices between US$300 and $800. The Duncan Designed club members include Fender/Squier, Jackson, ESP Ltd, Schecter Diamond Series, Hamer, and Aria Pro II.
The HB-104 is a high-output blade humbucker that's based on a design we created for England's Patrick Eggle Guitars. The guitar was short-lived, but the pickup lives on in some recent guitar designs from Schecter and Jackson."
So with that, I can't answer your question on how those HB104s would compare to a Screamin Demon and a Full Shred. I agree with PR3va1L that a Full Shred in the neck would overpower a Screamin Demon.
I have a Screamin Demon in the bridge and a 59 in the neck of my alder Tele. I like it - good versatile combo.