The A100 is ready to start shooting less than one second after you flip the power switch.
Autofocus speeds were excellent, as you'd expect. Typically the camera took 0.1 - 0.2 seconds to lock focus, and only a bit longer in more difficult situations. If the camera had to use the flash as an AF-assist lamp it almost always locked focus -- and quickly.
Shutter lag was not a problem, even at slower shutter speeds, just as you'd expect from a D-SLR.
Shot-to-shot delays were practically nonexistent. You can shoot as fast as you can compose -- or at least until you hit the buffer limit.
You can delete a photo right after it is taken by pressing the delete photo button.
The camera moves between photos very quickly, moving from one image to the next instantly.