I know Sony wants to move those high-priced 58 flashes they have now, and have inexplicably introduced two new amateur flashes, but there is no middle ground anymore. The new 58 is $500US. The 56 was a street price of around $300US. The two lower models are lower guide numbers, and have no professional features like the aux. battery connection on the side. I'd use neither of them for anything. If you're P.O.'d about this like I am, then let's launch a complaint campaign to Sony, to either introduce a suitable update to the 56 or bring it back.