Not necesarily. IB's are just the sales arm and accounting, at times, for the clearing firm. Be most concerned with the clearing firm. Just don't call him if you have an emergency trade problem, make sure the clearing firm has a live trade desk that is well staffed 2-3 ppl, and 2-3 rings max.
Which Dorman electronic as in aka Mirus Futures, Zen Fire? Yes, but last time I was with them only 1 on trade desk, don't like that, maybe they have more now. That's the only Dorman I know.