Man, I really wanna love these things. No, I mean, I like typewriters so much I put them in public parks. (Here's a photo of Lauren and I from one of the earliest events we did setting up typewriters in a park. We called it The Carriage Return.) But... the Freewriter and other devices like it just come down to one thing: Discipline. I have iaWriter on my Mac. When I want to free write, or get an idea down without distractions, or just pound something out, I open it Full Screen, turn on Focus Mode, and I get... exactly the same functionality as the Freewriter ... for free. All it takes is discipline. Turn off wifi. Close your web browser. Be serious about what you are doing, and just do it. But man... the gadget-hound in me still really really really wants one of these things... even at $500.
I agree — I think a lot of money gets spent by people who want to pay to be writers, but who never actually write anything. You can get exactly the same effect with pen and paper, or a text editor, or a distraction-free mode like you described. Still, I can't help wanting to try the thing out. It is a pretty gadget.
A lot of people miss the writing part of writing, and being a writer. They think if they acquire the tools of a writer, they will magically be one. But writing is just stringing words together, one after another, until you have forgotten there are other people in the house. That's the long and short of it, really.