> one click node editing

Yes the Webkit DOM inspector lacks that.

> css editing

It does have that on the other hand.

> the fact that it live updates the DOM as it is changed via any JS running on the page

My DOM inspector does seem to do that as well, though it doesn't highlight the altered subtrees the way Firebug does.

> DOM/JS object inspection

Has been in for a long time, though it could be missing some bells and whistles.

> having XHR logging in the console itself and not on another tab

Matter of tastes there, we'll have to agree to disagree as I'm not fond of this at all.

> Plugins such as FireQuery also make a difference for my needs.

Yes that I will easily give you.