Used Valterra on some nasty kochia land we rented last year. Very impressed with it, sprayed in October and planted large greens in spring. Not a single kochia weed this year. Still had a mess of wild oats, and I think fierce is supposed to control them but I have no experience with it.
We are in a heavy gumbo area, I hear of guys using in on lighter sandy land not having as good of results.