Wow, lots of different opinions there! Thanks to all.
Just to clarify, I don't need audio editors or all the superflous stuff that comes with Nero, don't need anything to rip or shrink commercial discs or anything to author my own (I use DVDLab Pro), all I need is something to reliably burn pre-compiled DVDs to the disc.
I've had success with CopyToDVD with the Sony drive and they specifically mention Plextor in the FAQ about which drive to buy, but doesn't Nero offer the only sure-fire way to set the book type of DL discs to DVD-ROM, or can Plextools handle that for all applications? In other words, would Sonic (for example) ignore the Plextools setting and write everything as DVD+R DL, therefore reducing playback compatibility?