I've noticed when using the "Flipbook" (or 'W' on the keyboard) the timeline plays with a better quality than when I use the "Playback preview" button on the remote control panel (or the button at the bottom of the Project window).The drawings seem to be a little bit more pixelized when using the "Playback preview" button.
Would it be possible to have the "Playback preview" play the timeline with the same quality as the "Flipbook" option? I think it would be good to have the extra control options (for instance "loop play") for a timeline playback with better quality.
And if "Playback preview" would play with same quality and framerate as the Fipbook perhaps we could lose the Flipbook option...?
This is a screengrab with the "Flipbook" playing at 25 fps:

And this with the "Playback preview":
