This camera has the same sensor of the Panasonic GH5s and records to SSD ProRes422 HQ. There is an upcoming functionality to record ProRes RAW using a Ninja V (the camera has no LCD so it needs a monitor anyway)
Nauticam makes a very cost effective housing (but you need an housing for the monitor anyway)
Drawbacks like the BMPCC no IBIS, lack of control, probably no custom white balance, proprietary software to decode their Zraw files (if you don't like ProRes RAW)
I would be interested in some real life experience the housing is really compact (as it needs a screen)