There is nothing wrong with FX spot on Interactive Brokers for example. Doesn't help the OP, since he is a U.S. resident, but still such blanket statments are nonsense.
As far as i know, there is only Gain and Oanda left, so nothing compareable really. I would probably go for futures in this case too. Oanda does have a commission-based model now too, but i have no personal experience and its more than double the cost than IB ($50/million).