Have been using for some time in Chrome on my work PC, now trying out also on Firefox at home. I actually really like how the add-on works. I see no slow-downs or glitches.

Some people are commenting that the descriptive titles tend to "spoil" the video but in my opinion this is exactly the point. You can always switch off the default replacements and then you only see the "dearrowed" description after clicking on the blue button.

The one issue I have is that since actual work of replacing clickbaits with descriptions is crowsourced, this extension needs more people using it. And I think for many people the short free trial is off-putting and they won't even bother to click "I don't want to pay" before uninstalling the whole thing. (I paid btw)
I think it would be glorious if the DeArrow functionality was eventually included in SponsorBlock which has a much bigger user base.