I think Aaron is correct that past a certain price point you are better off investing that money in factory motorized window coverings since you'll typically get 5 year warranty on the electronics and 10 years on the fabric (for roller shades).
I think it is wise to be skeptical of any device that promises too much, especially crowd-funded devices. Also be aware that retro-fit devices like these are for very small windows (unless you want the lightest, sheerest fabric possible for no privacy or light control as seen in the YouTube video). Also you never get to hear how loud they are, or how smoothly they run, or how slow they are.
Motorized window coverings aren't "easy" to get them done right. All of the major tubular motor suppliers like Somfy aren't worried about devices like this, and even used to sell something very similar to drive a drapery cord before motorized tracks and motors were created (a better way than add-a-motor). These types of solutions could be a great retro-fit device and might be good for small window shades, but in the Western U.S. windows are large and people want them covered in one large shade, so maybe elsewhere it might work. But it has to be the right price.