Upon looking further ...
there are 2 major concerns:
1. Where are the patches held ??, in the iPad (soon to be android/windows/Linux )
2. They make it sound like the system recognizes the song tone, when what it does is a "search" much like one would do on the Line6 site for a specific Artist tone. So, they use AC/DC in many examples and I am sure that they would get thousands of people submitting tone patches and That situation is susceptible to bad data in / bad data out.
Seems like a good product for the masses, which is probably the marketing & design intention
just my 2 cents
BTW, I have the HD 500X and enjoy it