Also just to add some balance and make it not sound like i'm completely disappointed. I am impressed with the speed of the watch.
I have a playlist i use for running, on my S3 i'd select that and then tap to go to the menu to select Shuffle. It'd take ages and sometimes time out. Went to do it this morning and everything loaded instantly. A huge plus
However, how do i play music with Apple Music on cellular? When i was out this morning and went into the Music app, i could only see my 2 locally stored playlists.