I searched customer reviews @ amazon worldwide, found only some @ amazon.co.jp.
The mediacode of the discs is mentioned nowhere , but there are many one star reviews. :doh:
That indicates for me, that they might be RITEK DR3. If thatÂ´s true, avoid at any cost! :a
Other possibilities are CMCMAG DI 6, which can be very decent in Pioneer writers from BD-R206 on, or VERBATIMf which I would avoid, too.:Z
Even if there is a "Made in Taiwan" sign on the spindle, all of the three mediacodes mentioned above are possible, because CMC manufactures VERBATIMf now, too.
If they are made in China, they could be TDK.