It seems that when I set up the Activities for A, B and C that I have to select my devices each time. For my setup it's the same TV (Projector) and the same A/V (Integra) but a different input and device (Apple TV, Blu Ray, etc.) So there is a good amount of overlap between activities. It might be nice to be able to share the already selected devices between all activities. I run into a couple of issues when they are unique per-activity.
Usually I have to hunt a little to find the right device. Try one, test it, see if it works. Then I'll find the right one. When I setup another activity a week later I don't remember exactly which one it was, so I have to edit the first one to find out and then go back into the wizard for the second.
The icon colors are different for each activity.. so they almost look like different devices on a quick look. Maybe there is some way to customize those so they match.
But possibly the idea between activities would be to use this remote for multiple different complete setups with different hardware? (i.e. bedroom vs living room)