In the meantime, I have burned 20 BD-R disc with 3 different burners (Plextor PX-B950SA, LG BH16NS40 and Samsung SE-506). There were no errors, so no committee. The burning rate varriert (of course) depending on the burner. Of all tested so far from me BD-R's of this were the fastest, where I carry out no exact measurements, but just at the beginning and end of the burning process "look at the clock."
The BD-Rs are printed with inkjet printers. Smudging.
For me, an important purchase criterion, because I have to label it for archiving purposes color my BD-R.