We'll know for sure how effective the process is once we actually see it. In the past a number of awkward design decisions have made it through to public beta before being withdrawn or undone. Occasionally the shiny can be distractingly alluring, and user-interfaces can be a major blind-spot where the notion of shiny can obstruct the assessment of usability.

What I think is reassuring is that they have teams these days, testing and reviewing aspects of the viewer, who apparently feel comfortable providing some quite blunt feedback.

It likely won't be too long before we see what kind of fruit that process actually bears. Even as it is, any major overhaul to the UI will see a lot of existing users scramble for third-party alternatives. A lot of folks still refuse to move to Windlight, after all.