I set my D700 @ ISO200 on a tripod and made photos in darkness.
The subject was the far end of a utility barn here on the farm.
Distance was 65 feet. TTL and full power manual photos were made.
I used the SB600, SB800 and SB900 flashes, & a White Lightning X1600 head.
I metered the X1600 to get the correct exposure at the back of the barn,
the X1600 was set at 1/2 power to provide correct exposure at f4.
Meter used was the Sekonic L-558, it's accurate and 100% dependable.

Lens used was the Nikon 85mm f1.8 @ f4. The lens was correct
focal to see the back of the barn, and all flashes were set to 85mm setting.
The photos are as exposed, unedited, except to resize for www.

Bottom line; all 3 flashes were acceptable, but slightly underexposing
while used at all out power on manual mode on the photos below. The TTL snaps look
exactly like the manual exposures, showing that the 3 have a range of 65 feet, but no more.
Also, the SB photos have a cool blue color cast which is not from underexposure,
as I have noticed this trait during general use of the SB's.