Personally, I hope they DON'T change the mounting system. My 705 won't fit onto my wife's 800 mounts and vice versa. As a result, my concept of "let's swap Garmins so I can see your HR/power while you can see my HR/power" (while each of us can see our own effort on our respective CycleOps Joule 2.0 units) isn't a casual change. I'd need to bring zip ties and wire cutters, which means she won't go with the plan. Nor will she let me upgrade to the 800 "just so it can be interchangeable with hers".