I would warn you that the G2 and Google music don't really like each other much.
The G2 has some type of issue with itself that makes using Google Music difficult to use. The stream will often interrupt and you will have to restart it. It also happens when listening to cached music from the phone itself. I would hope that the G3 does not also have this issue.
I'm sure not everyone suffers from this, but I do use the service extensively throughout the week and often cannot go more than 10-15 minutes without the stream interrupting. To be fair though, it usually will start back up after about 4 tries and is really only an annoyance at best. It seems to be exclusive to particular songs also, as I have more trouble with individual songs versus a playlist.