I've had good luck so far with simple ProMini/clone based loggers, with most of my builds drawing sleep currents around 0.3 mA (and I think most of that is the sleep current of the SD card itself - watch out for counterfeit cards)
I found that the cards went through at least two states. The new card immediately drops to about 500 uamp then sleeps at about 70 uamp . The old card immediately drops to about 200 uamp and sleeps at 60 uamp.
The 'RSV' pins are floating inputs. It is the responsibility of the host designer to connect external pullup resistors to those lines. Otherwise non-expected high current consumption may occur due to the floating inputs.