Be aware, however, that the same shutter lag seen when capturing an image while using the live view option on the rear of the DSLR is present here, too.
Tests of the virtual fence didn't lead to nearly as many arrests as designers had hoped, and the lag from sensor detection to transmission of an image to border agents was apparently a big part of the problem.
The much larger sensor and superior processing gives you massively better image quality, they're much faster (with little or no lag) so better for action, there's a lot more creative control over things like depth of field, the option to change lenses, add flashguns etc add to creative possibilities and also increase image quality.