And if I'm not mistaken, overnight margin requirement applies from 15 minutes prior to the US RTH equities session close @ 16:00?
I could live with $4039 intraday margin, although I think it's a tad too high. But $8000 per contract before the day is even over would not work for me at the moment.
So, I probably have to look elsewhere.
As to your question, I haven't had any other brokers than IB. Was really satisfied when I used them a few years back. Haven't traded since then, but am looking for a broker now...