Enjoying Superdense a lot. Using favicons is really great for most sites. Here are some specifics:

+ Cross-browser and device functionality
+ Simple, quick and easily editable
+ Ability to share links with others (privately or publicly)
+ Can have multiple category URLs so I can get really granular
+ Branding option!

I wish it had the ability to make some categories display a list-view instead of just favicons. I'd also like to be able to privately share one of my category URLs (or even better just the category) with a special private link or password.