Well for cookies chrome only shows the value, gives less control than firecookie. Other extensions seems 'hacky' solutions, doesn't feel integrated, some time slow. Also for css editing like add style, increasing/decreasing css rule value firebug is still better than chrome inspector (chrome still does not support increasing/decreasing in metrics tab). But javascript debugging experience is better in chrome. Chrome has good profiler, can add XHR breakpoint, listen for various event listener.

On an unrelated note I can't live without tree style tabs(On average I have 30+ open tabs, which is unmanageable in chrome, hangs some time) and vimperator. All in all I still prefer firefox.