This is to share on information about a "generic" BD-R DL I tried.
Purchased a while ago from MicroCenter (I don't recall when).
They were inkjet printable, packaging read ValueDisc 50 GB, BD-R DL, 6x, 260 HD Min.
Checking with Nero SpeedDisk:
Media ID code was: VERBATIMf (000)
Write Speeds 4X - 6X - 8X
I prepared a 43 GB image file with TMPGEnc AW.
I tried several different LG (MDisc-capable) BD burners.
It would not burn the image to disc using TMPGEnc AW, NERO, or ImgBurn
at 4X speed.
In some cases the burn attempt would lock the burner (not the PC) requiring a PC restart.
Tested burn speed with Nero DiskSpeed. Turns out burns speeds ranged 2X to 3X.
Burned the image at 2X and the resulting burn scanned with no errors.
It also played OK in an older Panasonic BD player.
Off brand media may not work as advertised.
A slower than "specified" burn speed may work with problem media.
I will use them for low importance burns at 2X speed, never for anything important.
(FWIW: The LG burners have worked well for me with CMC , Tayo Yuden, JVC, M-DISC, and Verbatim-branded CD-R, DVD-R, DVD+R DL, and BD-R media.)