There is a report that the battery life is better than expected. I hope the housing companies make room to put in the external SSD, as that will save you $2000 to buy CF card that's fast enough to shoot RAW.
The focus mechanism of the BMPCC4K is basically just like using "Back button focus", it's the style I have been using for years.
The deal breaker for me is no any sort of IS.
Panasonic will announce their Full Frame camera on Sept 26, so it seems like every few months we have something new to look forward to. There is no point to pre-order the BMPCC4K at this point.