Late answer... The Gately point associates to each player a payoff proportional to his marginal contribution to the grand coalition. The proportional coefficient is uniform and is computed so as to satisfy efficiency. It is therefore also symmetric. It obviously satisfies the null player property but it does not satisfy the dummy player property and is definitely not additive. Another problem is that it does not satisfy individual rationality. Concerning monotonicity, there are several definitions and I guess that the Gately point satisfies none of them. The equal surplus rule has better properties: it is individually rational, symmetric, additive and satisfies aggregate monotonicity. It obviously fails dummy or null player.