With the 30 IPC rule, I have not lost a game as the Allies and have not won a game with Japan (though I came close once). Now, we admittedly do not play Pacific or Europe standalone very often.
That being the case, the 30 IPC rule is a bad rule. It should have been 30 IPCs worth of infantry, not 30 blanket IPCs that the US can spend however it likes. That would have prevented the US from spending money on submarines to go after Japan a full turn early, or it should have required a Japanese attack in North America before the US gets the IPCs. Giving the US 30 IPCs to spend as it likes just because Japan does a DoW on anyone just makes for boring and predictable games.
Marsh