I have to admit, I use the BD-RE discs less and less. Takes too much time to write to them. I use them now when I'm none too sure I've authored something correctly to AVCHD or blu ray format. Testing purposes primarily, in other words.
Do you happen to know the mid code on these Memorex 4x that are on sale? The ones I had were Ritek BR2-000. The one Ridata disc I had with the same mid code was still readable, but it was deteriorating and showed some slowdowns on a TRT scan.