A77 & flash for macro
If you use the A77 internal flash for the commander, the delay is virtually instant--although it is slightly longer than with the A700 or A900, but it is very good. If you use another flash (like the F20AM) as the wireless commander instead of the internal flash, then the TTL delay is quite long (~0.4 sec).
You won't notice the delay if you use the internal flash as the commander.
Steve W weather photos: http://home.comcast.net/~scwest/atmo/