Visualization Training

The reviews on Chess Visualization software are mixed--some claim it helps, some claim it doesn't help. Here are some experiences and studies:
http://chessconfessions.blogspot.com/2007/12/review-chess-visualization-course-book.html
http://chessconfessions.blogspot.com/2007/06/board-visualization-does-it-matter.html
http://chessconfessions.blogspot.com/2006/11/chess-visualization-web-and-software.html
Found this site, where it has exercises like guessing what color a square is based just on its notation etc: http://chesseye.alexander-fleischer.de/o/
Wondering if any strong players have done similar training and found it beneficial? My feeling is that there's probably better ways to spend study time, but on the other hand I have poor visualization, especially trying to follow notation strings. Anyway, thoughts and opinions on this kind of thing?