In this version I changed "+refs/tags/*:refs/remotes/tags/%s/*" back to "+refs/tags/*:refs/remote-tags/%s/*" as Junio originally suggested. This way don't have remotename collisions as Bryan pointed out.
Since I don't like "--prefix-tags" I changed the option to "--remote-tags" but obviously open to anything else. I think jacob.keller (+ demerphq) suggestion is probably good, but for the moment just using remote-tags as seems simplest.
