Yes, it's true, you must be in the sweet spot. This kind of setup would not be good if you have multiple people in a room listening or watching a movie.
I have a small dedicated listening room, so I don't have those concerns.
Just for fun, you should grab two of your surround speakers and set them up for holography and see what you think. Also, it's not really producing an effect; it's correcting the imaging-flaw inherent in regular stereo playback. You can read more about it in the manual (linked in my last post).
As I said earlier, I like it so much, I no longer listen in stereo.