I am also still struggling with this issue.. by the way I am going to use YS-DS1 with mirrorless LUMIX GX1 with nuticam.
I set it on DS-TTL II and had very good results with my 7D. The "other" slave seems to be for non-compatible cameras. I did have the lock up issue that was supposed to be fixed by the recall. Backscatter gave me two replacements. I'll test them in real water next month.