I use the Android version ("OK Google") for a few basic functions. #1 is getting directions home while driving - "OK Google; navigate home." It does that pretty well. SMS dictation while walking, or while just not wanting to type out an email generally also. It's probably better with texts purely because they tend to be shorter with fewer opportunity for error. With something longer like an email I always have to correct a few errors, then wonder if it would have just been faster if I typed it out myself.