IB's Globex connection went down today for over an hour, during which time two of my stops were hit but never filled. I called the help desk and was put hold for 30mins. There was a recording that said "sorry Globex is down" but I suspect it was only down for IB. Then I went on live chat and the guy chatting with me knew absolutely nothing, could not tell me if I was net long or short, could not tell me if my orders were filled or not, and didn't even say sorry or anything for the problems. Not to mention it took him 5-6 mins to answer each of my questions.
What if I was an EOD trader or just happen to not be at my desk and the system went down? I couldn't offset my position with another broker. If they are having problems now (and have had problems with high volume from what I've read elsewhere), can you imagine a crash scenario with extreme volume? If IB's interface goes down then you'd be wiped out even if you had a stoploss order set. If it's only the IB interface going down, that is not as bad as your stop orders will still be there.
In any case, today's outage made it perfectly clear to me that IB is too risky. Yeah it may hapeen only two or three times a year, but that's too risky for my blood.