When it comes to MLV RAW -- I've always liked the results when the 5D3's at ISO 400 give or take. Used to think it was ISO 800 until
@quickhitrecord &
@baldavenger's each separate experiments which proves otherwise respectfully.
But in here we are talking about log styles being recorded into H264 format (not RAW) which is a whole different ball game and we normally (or at least should) shoot them in increments of ISO 160 such as 160, 320, 640, etc...
I've also noticed that 5D3 likes to sit at ISO 640 (either close down or use ND) or drop down to ISO 320 which seem to have slightly better shadow noise than at ISO 160.
FYI -- when we use C100II out on the fields at where I work -- it's 'sweet spot' is actually ISO 850 which is also being recorded into Wide DR custom profile (rather than a flat log) due to quicker turnaround workflows in post for broadcasting contents per Editors/Producers requests.
Guess it all comes down to how much time do we have in post to determine whether to shoot in a customized profile look or a flat log, right?