The Echo 15+ Pro with Matshita BD-MLT UJ260AF burner burns all disc types properly EXCEPT DVD+R DL 8.5Gb Verbatim and Memorex discs. Toast 17 Pro (as of build 5470) consistently hangs at the Writing Lead-in burning stage for DVD+R DL 8.5Gb. The burner works fine when connected to the computer via USB 3, but there is some kind of latency issue when the burner is connected via Thunderbolt. Sonnet does not have a solution at this time.