[madsteve]

Cricket is slow anyway and periods of excitement are usually sporadic.  Football is unique and it will wreck the game

In 90% of matches, there would be no difference as there wouldn't be a decision to be made. In 99% of matches, there would three or less decisions so it wouldn't wreck the game. The best thing would be to trial it for a year but on the basis of an official in a box reviewing rather than Managers having reviews.