I have tried a lot of media (4x, 2x, +r, -r) from Verbatim, Taiyo Yuden and Ritek. I am assuming the 4x and 2x media I buy is really 1x-4x and 1x-2x but I have never been able to burn a dvd at 1x speed. Even if the software lets me select 1x (which is not always the case), it will still burn at 2x. It could just be the media I am buying because DVDInfoPro will not even say that 1x is an available burning speed (on anything I have).
The one thing I haven’t tried is to buy 1x media, but I am worried that the drive will not allow me to burn that at all. If anyone has had success with 1x burning on the 411s (with the more recent firmwares) please let me know.