I have had a Surge for approx four weeks and havent missed this as I'm using a Garmin Egde computer anyway.
However I have got 3 Q's regarding such functionality during this weeks from people interested in the Charge HR as a replacement for their HR cheststrap.
Would be a nice feature espesially for cycling. Surge doesn't support cycling yet but I dont think the coming cycling mode for outdoor cycling will offer the same features as Endomondo anyway.
I also like the voice "coach" in Endomondo
I would be very nice if you could pull the data HR data from Garmin or Endomondo and put in to your fitbit. becasue when I am traning on my bike. I can see my heart rate on my fitbit. And for that reason is better to use my Garmin Egde. Where I can see all my data. But I would have been great if I could have transferred those data