Wow...a hot topic indeed - the thread just started today and we're at 4 pages already!
As one who tends to have trouble sleeping on a flight (even in Business class) , I try to catch up on work on a daytime flight (usually TATL) and would much prefer the window shades OPEN. If shades are closed, inevitably, I have to turn on my overhead light...I feel that they shine not only on me but affect those around me; whereas if shades are open, there's enough daylight that I can work without the overhead light, thus bothering fewer people IMHO. Also, I tend to dim the screen on my laptop, and this is fine with daylight to see; but again, if working in a darkened cabin, I have to brighten my screen, creating a "glow" and I believe that disturbs those around me.
If I happen to sit by the window, esp in economy, I will, if requested, agree to HALF lower the shade if those next to me are getting too much reflection on their IFE screens.