Didn't Titanus put out something similar thru Murphy's a year or two ago? Slightly different application, being that his version would play thru the radio but same general idea: Think of a song. Name it, and it plays in an impossible way.
So I can tell you right now without even owning this product: It isn't going to be what you're expecting. It's not going to be impromptu, and it's going to require someone, a secret helper, to assist you with the magic monkey business. Having said that, along with the price tag associated with this product this will NOT be for everyone.
However
IF you CAN work with it, and find a way to utilize it, then this is a reputation making miracle in your pocket. The down side is that it's very intimate. Being that it's only for one person at a time, as the headphones are kind of important to the delivery of the named music. So I'm not sure if this would work well on stage. And having a secret helper for anything street or strolling may not justify well for everyone. So ehh.... 60/40 if you ask me. I'd really have to get a unit, and review it in person to be able to levy a better opinion on it than this. However from what I've seen of other reviews, and what I can see from the trailer I'm going to stick with that for now.
Is it worth it? I guess the question to answer is: Can you make it worth it for you?
Answer that and you'll know where you stand.
Ellusionist or Adam if you guys want a fair (or at least fairer) review on this product then you know how to contact me. I'd be more than glad to give you a fair opinion.