Ok...So I just bought a 945. Today I went training with my f5x+ and after my workouts sync my new fr 945 to my connect iq. After a few minutes the data from my f5x+ was analysed by my fr945 and gave me all the new metrics without using my fr945 to get them.
So for 800$ (canadian) you can also get the new firstbeat features with your 5x+...
But seriously, this kinda prooves our point that all of the features (new ) from the 945 are software only and doable with the f5x+ software...garmin make it happen.