I used to use Enhancer for YouTube and have been looking for a replacement for this feature ever since. I gotta say, this one works pretty well. However, I have some suggestions for it.

1. I would appreciate a better contrast (like adding a darkened background) so that the value is visible during white video parts too.
2. A cool feature to have would be changing the value simply by scrolling over the marker, which would free up one hand.
3. Consider moving the marker from the top right of the video frame to the video tool bar, so that it can hide automatically.

Thrilled to see this came to Firefox - one of the most useful YouTube addons available. Unfortunately, it often remains on the screen even with Hide/Show Playback Panel selected.

works well. If I could improve it, I'd give the user finer speed control (increments of 0.125 instead of default 0.25).

not work reset (*)