Through the Home -> Activity page, you can filter to see progress that each user has made over time. On the Home -> My Work page, you can also view To-do's for each user and "impersonate" to a degree.

We are unlikely to build an impersonation feature as the general Aha! experience is the same across all users, and we also do provide the ability to change roles/permissions through Account Settings (if you are an Admin), which can be another way to view Aha! through the lens of another user. I hope you can understand.

Why isn't this going to be implemented? It would be extremely helpful to view exactly what my users see.

I have also been trying to figure something out for this. I agree that the impersonation in Aha itself is OK, but we really need a way to impersonate a customer who is using the Ideas Portal so that we can confirm what they're seeing visually (instead of just reviewing individual fields in each idea).