I see that Plextor 716A media list (USA) website has changed. There is no Recommended and Compatible media anymore. The Plextor Europe media list website remain the same though.
According to the US website, these are the best media:
Taiyo Yuden: DVD+R/-R
Verbatim/Mitsubishi Chemicals/MCC: DVD+R/-R/RW/DL
TDK: DVD+R/-R/-RW (no +RW listed)