I noticed you asked the same question in another thread. Those rates aren't that great. Not terrible, but not great. Interactive Brokers offers $2.40 per side. $2000 minimum. Global requires $5000 if you want J-trader. IB offers $2000 intraday margin for ES, although I assume you quoted the overnight margin.
Yes, yes, I know, too much margin is a dangerous thing. It never hurts to have double or triple the exchange minimum margin. I don't like brokers that don't quote their commissions on their websites, although that seems to be increasingly common. I'm not bashing these guys, just countering what seems to be a plug. Does anyone have any experience with J-trader? I know its available at various firms.
BTW-I couldn't get their J-trader demo to work, but that could be my computer.
Snake