My original review was written when all I had done was deposit money and make some trades, now that I have had the misfortune of dealing with Questrade's customer service staff, as well as having had the audacity to attempt to make a withdrawal, my view has changed drastically.
QT is the classic business where every CSR tells you something different and none of it appears to be correct (that's once you wait on the phone for half an hour to speak to one of them of course). They also have an online chat, which works like MSN, but also takes forever because they verify your identity one message at a time and each new message is sent and received at a painstakingly slow pace.
Most offensive is that I have been trying to get my money out of my account for over a month now and still do not have it (despite numerous hours devoted to calls, e-mails and chats). Basically if you want to trade on the cheap and have no interest in actually being able to withdraw your money, QT is for you. I also agree with Edwin's comment about the accounting being slow/unreliable.