Not bad! I was previously using a combination of the Georgify and Collapsible comment extensions. Your extension is better in some ways and worse in others.
Suggestions: Collapse link shouldn't be on the far right, and collapsed comments should only show 1-2 lines regardless of actual length. Link color brightness could be taken down a few notches. Reply link shouldn't be underlined.
Suggestions: Collapse link shouldn't be on the far right, and collapsed comments should only show 1-2 lines regardless of actual length. Link color brightness could be taken down a few notches. Reply link shouldn't be underlined.