Distance doesn't matter. It's all down to how many degrees of your vision that the screen takes up.
That makes as much sense as saying it's all down to the area of the rectangle, the length doesn't matter. Field of vision (degrees) is a function of screen size and distance just like area is a function of length and width. Most of us sit way closer to the monitor than the TV, not just absolutely speaking but relative to the size. I just did a quick measurement and found I sit about 60cm away from a 28" monitor. That means I should sit 120cm from a 55" TV or 240cm away from a 110" TV for the same field of vision. In fact at the back wall of my living room at about 4m I'd need a 180" projector. So if curved only makes sense for big fields of vision, we need to sit way closer or buy way bigger TVs. So I think for typical living room distances the answer should be to give us reasonably priced 100"+ TVs first, then we can talk about curved.