I wrote about why I really like Flow here: http://blog.garrytan.com/why-flo...
TLDR is that this thing makes making adjustments on sliders a thing of the past. No more trying to acquire a target on a slider 100x and then not being able to hit a value in between two of the pixel notches on there.
Great product! I'm always a fan of more human interface devices—keyboard/mouse seems far too limiting. And the dream to combine the physical and the digital is awesome.
It seems like the advantage of this over Griffin's PowerMate, which is a similar wireless control dial, is the touch and gesture control available with it. That seems like a pretty huge upgrade that makes this more than just a "control dial" but more of a multi-input device.