Sad that 4.0 has yet to arrive. Glad that they continue to do these minor upgrades. Lightroom is still better for overall processing, but Aperture is necessary if you are a hobbyist, like me, that utilizes Apple's full ecosystem.
"The bad news is that depending on where you buy it, the MB-D12 will cost you between $450-616, and that's not including the cost of an additional EN-EL15 battery (necessary for the speed boost in DX format)."
Barney, you actually need to use AA batteries or D4 battery to get the DX 6fps speed boost.