Google Music Disappointment
I love everything about GPM All Access except the most important thing: new music discovery.
Music is exciting when you stumble upon exceptional individual songs. The Music Genome Project was such a brilliant solution to music discovery (despite Pandora's horrible use of it), because it understood that people like music based on specifics sets of characteristics of individual songs. The critical shortcoming of Google Music is that when you start radio from a specific song, it ignores the actual characteristics of your source song and recommends music based broadly on the entire music collection of the artist, or on the album, or on some industry dictated theme or genre.
The result is a stream of horrible music, utterly unrelated to the source song. A good example (whether you like the song or not is irrelevant) is Human by The Killers. It's an upbeat electronic song, but if you start radio from it all you'll get is depressing rock songs.