To put it briefly - the failure rate was my copies (5 pcs.) At 0% and the write speeds used at all.
Other BD player in the household can easily read the written blanks. Of course I can not say anything yet about the data resistance because I'll probably add a response in 5 years :)
Conclusion: if you are not so stingy to take some money for intelligent disk in the hand -> strong buy recommendation.
Incidentally, the same blanks there should also be on the spindle, where you can get the same price equal to 10 pcs (no LTH, but exactly the same as here). I can do without plastic bags, I'll try it.
