Personally, I prefer to pay $10 a month, and have access to their whole catalog, the same way RDIO/Spotify/MOG work, but I guess that depends on the individual (I usually spend over $1500 a year for music, so I want to cut down on this addiction).
What really rubbed me the wrong way though is their supposedly-new "Artist Hub" feature: for $25 signup fee, "bedroom acts" can sell their albums via Google Music and give up 30% of the sales. The thing is, Bandcamp is doing exactly that for over 2 years now, they have $0 signup fee, and they only take 15% off of sales (plus, most music there is given for free anyway). $25 might not sound like a lot to most people, but having personally worked as a music video director for some of these bands (for free), these acts simply can't afford this one-time fee of $25. Some of these artists are living in slum conditions (I have real-life examples).
Sure, the Android developers pay the same $25 to get access to Google Market and sell their apps, but Google Market is the only store Android users go to buy their apps (Amazon Store, or iOS ports are rare for most Android developers and their apps). But for music, customers buy music on thousands of little or bigger online or not stores, and each distribution channel requires its own fees from the artist. Quickly, this becomes unmanageable! The artist's "choice" to not sign up with most stores in this case is only theoretical, to find the reach he/she needs, he must sign up. That's why an additional $25 for Google Music accumulates more than it would for an app developer.
So, signup for unsigned artists must become free (or at a nominal fee of $1, for legal reasons). If Google wants to embrace indie, then it should go truly indie, and not half-way.