A dive-friend and myself BOTH have this setup and have had GREAT results.  The large screen is easy to see thru the case.  Lag time on taking picture is minimal.  We found that the “Food Mode” of all things takes the best photos (lighting, focus, etc.) for fish and coral at close range.  We did a lot of testing of other modes ... at 0-100ft deep in Fiji’s “Rainbow Reef” (www.fijifiji.com).  We also used the camera’s own flash alone and also with an attached slave-flash ... both worked well.  I would be very interested in feedback from other divers using the same Casio setup about their settings and suggestions.