I tend to be against general sliders, based on personal experience...
People have very different ideas of what one 'notch' on a slider means, leading to more noise;
Anchoring effects on sliders are super strong. If you anchor it in the middle, people submit very low-variance responses around the anchor, and if you give no anchor at all, people tend to get confused about how to click the slider.
Currently, we do everything with likert scales. Any reason we should change this? If so we'll need to build up sliders (https://github.com/Watts-Lab/deliberation-empirica/issues/424)