I don't think the point is to let you switch between different versions of an image (though the after-the-fact adjustments of depth of field are really slick). I think it's more that with a bunch of sensors and lenses you can simulate a much larger sensor and lens, so you get the low noise and choice of lens profiles of a DSLR without having to actually lug one around, or a bag of lenses to go with it. Some of those pictures in their gallery are pretty awesome, particularly in terms of noise. I'd never have guessed that they were taken with something so portable.