It can be confusing for new users to know what waveform settings to use. I propose adding a simple auto-detection process that basically automates current best-practice:
1) Try each available waveform option for a few seconds each in succession with frame rate slider at max, noting frame rates.
2) Select the one that provides the highest frame rate.
3) Lower the slider little by little until there are no (or minimal) dropped frames.
This should run silently and automatically at first-run (i.e. no Mixxx preferences found,) and should be available to re-run from the Waveform preferences pane.
After this is in place, we should separate the waveform options into appearance (RGB, HSV, Filtered, etc.) and rendering method (software, GL, etc.) so that users can choose the appearance they like and let the wizard determine the best rendering method.
A quick bandage solution would be to present a dialog on first startup advising users to try the different renderers and adjusting the framerate.