There is a guy at my firm who made one million dollars in one week trading CME yen futures while Wall Street was liquidating LTCM positions. He gets very opinionated, and needless to say his P&L swings are not for the timid. He bullies the rest of the market into seeing things his way. All he does is pace the office floor and rant and rave while he keeps adding to his position. He doesn't bother me much because he trades Far-East and European hours. Morgan-Stanley, Bear Stearns, and HongKongShanghaiBancorps (HSBC) hate his guts and really go out of their way to butt heads with him.
I would look at the bid/ask spreads between the futures and the bank cash market. If they're comparable, I'd have to think that the execution costs and tax advantages for the futures would make the CME market more favorable for the little guys like us.
The richest guy at my firm trades CME currency futures. (and he's not the guy I've been talking about in this post) Used to be the top trader for a very large Japanese bank. Likes the Euro currency future. Stinkin' rich.
I'm the weirdo in the shop trading interest rates.