I've also been using Google Play Music All Access since it released. I prefer the interface to Spotify's (specifically in the ways you can browse, Spotify is based primarily on search where Google gives browsing and searching equal footing.)
I will likely not get Apple Music based on my experience with iTunes Match. Google will consistently stream as long as I have signal on my phone, and does a fantastic job of predictive buffering. iTunes Match on the other hand is basically unusable while driving and the vast majority of the time won't even start playing songs unless they have been downloaded ahead of time over wifi. Apple's infrastructure can't have gotten that much better in such a short time. I might give it a trial run, but honestly I'm not sure as I'm so happy with Google's product.
