Destroying bad

So, I do not review many products yes, but there's got to be easy. As shown in some reports there are apparently a massive quality problem in these blanks. I thought that the problems of old ausgelutschten burners caused and because for me it has never problems with blanks of any kind and which manufacturer was, I do not begrudge me this just once.
The balance is, however, damning: Pro successfully-described blank there are on average 4 to throw away.
I tried 2 burner: LG and an external Samsung, both with the latest firmware. Repeatedly crashes when switching to the 2nd layer. The blanks are total scrap and really not recommended.