Yesterday I had some time to test firmware 4 on some dancers. Its an improvement over firmware 3 but its nowhere near the AF speed of an DSLR. And maybe I would have had more keepers with AF-S then AF-C. Maybe its also because the light in the room was not that great. Hopefully in the next 3 to 4 years the mirrorless cameras catchup with the DSLR performance so I can leave those big cameras / lenses at home.