To outline my strong objections to this in one place:
In itself: Negatively: no big deal: Vandals vandalise a little faster? but soon blocked anyway. Edit warriors can go faster? but warriors will war regardless.
Positively: maybe, at best, a little help Lots of people want it to be faster on the draw. However, since in most cases of spotted vandalism six people fight to roll it back, the benefit to the project is negligible. There is no backlog of reverted, yet identified, vandalism. The only conceivable benefit is that it keeps the plebs happy by equalising their 'success' rate in the revert race with admins - I suppose that's not a bad thing, but little to be excited by.
in term of process - admins granting it Negatively: *Increased instruction creed and policy pages *Time spend handling requests *New process - we already have a 'requests' page *Process for removing it will be required *Process for handling appeals against admin decisions will be required *Disgruntled users who are refused it *Disgruntled users who object to x being granted it *Conflicts between admins - wheel wars - ANI reports and arbitrations
People say, "how is this difference from block/unblock"? It isn't. But block/unblock disputes are already incredibly disruptive and clog up ANI and arbcom - and we agree blocking is useful.
Positively: can't think of any
Conclusion Very minor positives, huge negatives. Combine that with the dreadful disruptive and manipulative way this was rammed through and this is a considerable detriment to the project.
And I have ignored the argument that scripts make it redundant anyway for those who really want it.