Virtual Inputs have proved to be a VERY useful, and time saving feature. I have 96 VT's, each VT has a series of triggers, positions, and transforms. Instead of having to set up every VT input separately, I created on VT input, set it all up with the correct triggers, positions and transforms. I then created 95 copies of it using Virtual Inputs, and then just went through each one, changing the input file to the correct file. I did not have to sett loads of triggers, positions and transforms to each individual input, and thus probably saved my self many hours of work.
I have also found them very useful when setting up multi view inputs, where I have had several 'similar' requirements - maybe just one element being different, but I can create a whole second virtual input, and then just change the single element in that composition, without having to set up the whole multi-view layout a seconds time.
All The Best
Keith