I've just run the numbers my self and what Awsomeness says is true, the math is correct. Furthermore, he is right that the early and mid game bonus of this is negligible at best and that late game 100+ cities it is just enough to keep me interested in even using favor. saddly, people fail to realize just how slowly favor is actually gained.
on the other hand, I see the merits of many of the self proclaimed "aggressive" players and I assume that a majority have not experienced the grind of the late game as it stands and the impossibility of being a great attacker that takes cities from active players. I enjoy early and mid game attacking as much as any loyal grepolis customer, but, with the advent of attack alarms coupled with players having 50+ cities per active player that are pumping out bis LDU at a significant rate, it becomes a hassle just to time all 80 of your attacks then hope that you alliance mate timed in theirs as well so you have a shot of clearing a city stacked with 300K bis. Therefore players are forced into simming because the game becomes a job and it is just easier. so, I support this idea just because people can grow a tad bit faster late game and get to conquer a city that mush sooner.