Battery life status...
Another month on, two more packs of film through the RF70, and the battery indicator is still showing all bars when I power up the camera. It now will display one bar down if I use the flash for three exposures.
As I get to know the RF70 more, I'm even more delighted with it. The SLR670 series cameras are more versatile and often produce better photos because of that, but the Instax Wide film is more consistent then the Polaroid Originals color film. It's a trade off, I like both cameras quite a lot.
Latest set of photos with both cameras here: https://flic.kr/s/aHsmDwgmVW