I know there are quite some questions around about this topic, but still I'd like to say something about it.
IMO, the logical way of editing should be something like:
novice user- no editing rights
advanced user- can edit (needs approval), can approve edits with 2 approvals needed, ties in approval need to be solved by 3rd user *
expert user- can instant-edit, can instant-approve (no second person needed), approval on edits which already have 1 approval (from an advanced user) does have more weight, thus no ties will occur *
* approval meaning either approve/reject in this context
Also it would be nice to make it dependent on the experience of the user (having badge in at least one of the tags/having editor badges) rather than depending solely on Reputation.
Maybe this is against the simplicity-rule of SO, but the system as it is atm is not very convincing.
edit in Reply to Wladimirs comment:
at the moment, the point that bothers me most is having instant-edit rights but to approve a post, there are two reviewers needed regardless of experience. Also the advanced approval right could be granted earlier to accustom users to participate on SO. Also the persons who approved/rejected an edit are visible at least in the devtools on 10k rep. But i wouldn't mind including it directly in the history page of the question/answer.