Objectively seen Firebug 2.0 has many small features, which the Chrome DevTools do not have. Some of them are listed here:
Console panel
- Displays XMLHttpRequests including the whole request information
- Displays cookie changes
- Some more Command Line API functions
- Separate Command Editor
HTML panel
- Inline editing with auto-completion for attibutes and CSS styles
- Options to control whether to highlight changes, expand them and scroll them into view
- Options to control entity display
- Quick Info Box
CSS panel
- Displays the page's style sheets in a formatted way
- Selectors side panel
DOM panel
- Displays all DOM properties in one place
- Displays closures
- Allows to filter the display by properties, functions, etc.
Net panel
- Allows to stop on XmlHTTPRequests
- Shows cache information per request
Cookies panel
- Create and edit cookies
- Control over cookie permissions
- Shows raw and formatted size of cookies
- Allows to stop script execution on cookie change
- Export cookies in standard format
General
- Open HTML, CSS and JavaScript in external editor
- Allows to customize shortcuts
A "feature" that goes beyond the usability is that Firebug is open source. So everyone can participate on it.
Having said that, the Chrome DevTools (as well as the Firefox DevTools) have many more features and other smaller and bigger advantages over Firebug as the team behind Firebug is very small in comparison to the teams behind the other DevTools.
Also, Firebug 3+ integrates into the built-in Firefox DevTools, which means those versions inherit all the features of the Firefox DevTools and may add additional features.
