MB Trading has a good commission schedule, but I actually lost more money with them then had I used a full service broker. They are unable to forward necessary shareholder information to exercise rights etc., although they have all contact info including email. Instead, you get swamped with useless brochures. They don't admit errors. When you ask customer service, they blame their clearing firm Penson. When you call Penson (difficult to reach as I am not a customer of them), they blame MB Trading. Inquiries are not answered by the time promised, but get lost in their system. Shares in the margin account are loaned out heftily to other brokers; they are unable to state their hypothecation policy (apart from the fact that they can do anything in they want in your margin account). I'm giving up now to reclaim my lost money. Over time you lose more money than with other brokers that have clear communication and policies.
Where are you going to go? It seems as all of the brokers have their share of problems.