I have not used it extensively, But. I have taken several shots with a SB910 on the camera as the master, and 2 SB800's as slaves. Every shot had all flashes working every time. I made no adjustments in the camera menu. All TTL lighting settings were set in the flash units themselves. Flash groups were properly sync'd. I will not attempt to offer any technical or exposure advice, as I am just barely getting familiar with the system. I can only offer the experience that it worked every time.