The problem with Memorex blanks used to be (and may still be) that while they may burn OK initially, the disks tend to become partially or completely unreadable as soon as one year after burning. This I can say based on my own experience over the years and that of many others. I don't know if this bad rep is still warranted, but I'm not interested to run the test.
Verbatim has worked consistently well for me for over 10 years, with one exception: I recently noticed that burning audio CDs from compressed formats in iTunes doesn't work on my iMac G5 (late 2005) and MBP (early 2008), both running Leopard: the blanks are ejected untouched. It works swimmingly in Toast, however. Go figure...
It will be clear from the above that I wasn't exactly pleased when Walmart and Sam's Club (my local source for Verbatim blanks) switched from Verbatim to Memorex earlier this year.
And before I forget to mention it, I have used Verbatim DVD+R DL disks with good results: no coasters yet...
