Many acres of ridge till in Central Nebraska.  Personally, we have gone from conventional till  and gravity irrigation to ridge till and gravity irrigation, to pivots, no-till, conventional tillage, and back to ridge till and everything is pivot irrigated.  For me, ridge till is the least expensive way to farm.  The extra pass I make though the field in the summer with the cultivator/ridger costs less than a post spray on my corn.  On beans it avoids a second post.  We run a root slicer/stumper in the fall or spring to clean off the old corn stumps if the field was corn.  If it was beans we plant right on top of the old row.  With the wet spring we've had this year ridge till looks excellent..