Why is there a delay when the DigiSnap 2000 is triggered to the time the camera actually takes a picture?

The delay can vary quite a bit, depending on a lot of things. First off, rather than a simple electrical signal to trigger the shutter, there is a communication process between the DigiSnap and the camera, which takes a little time to tell the camera what to do. Sometimes the camera isn't ready to accept commands, and it takes an extra long time to 'wake up'. Second, the camera has to set exposure and focus. This is highly dependent on camera model, and the actual scene. On some cameras you can speed this step up by manually setting the focus and exposure. The Nikon 990 and 880 have an additional remote control feature to preset the functions (half-press mode), which can dramatically reduce the shutter delay. The delay can be from a few 10's of milliseconds (a guess) to a few seconds in the worst case. This makes it impractical (or at least very difficult) to acheive true synchronization between cameras. Trying to trigger a digital camera via the DigiSnap to slave to another camera or strobe is just not realistic, IMHO.