Personally, I think that, while playing a game, evaluating past positions with a computer gives you a huge advantage. Being suggested a move always means asking "why", and often leads to a change of strategic objectives that often have impact in the endgame, much later. Often Zebra suggests a certain move several times during a game played on the board, and if players knew that would certainly have changed their point of view. Even looking only at past opponent's moves, IMHO, gives a lot of hints on how to play. When playing on IYT I discussed a lot if it can be considered "cheating" just evaluating with a -passive- board instead of pure brain thinking on the position!
(hide) Play a game in real time with an online opponent! For this to be possible, you and your opponent have to select the action "Move and stay here" as default and then reload the page with the F5 key! (TeamBundy) (show all tips)