Princo 4x -R = 15 min
Sentinel 4x -R = 22 min (red insert, grey top)

The Sentinels are a little better for DVD-Video playback (I got 4 glitches with the Princo's and not with the Sentinels).

The Sentinels, however, show that they are manufactured by Optodisc.
Is this a "bad badge" that can't write at 4x or what?

Has anyone tried Optodisc 4x -R (or Sentinels 4x -R)?