Questrade are absolutely fine, anecdotes are just anecdotes.
IB are also fine, though honestly QT tend to get back to me a damn site quicker than IB do (two weeks for a reply to one ticket, for instance, with IB).
IB: Cheap margin, cheap foreign exchange, flexibility. IF you have > $100k, absolutely, go with IB.
If you have a smaller stash and want to regularly buy ETFs? Go Questrade. Fee free purchases means you can (and I do) buy 1 or 2 units of ETFs (why would I do that? RESP).
I don't "love" Questrade, but from Cathy's writeup they are "the worst thing ever". People have issues with RBC, Scotia, IB, TD, QT, every brokerage or bank out there have *some* dissatisfied customers.
*Edit* but God OP ditch that fund. You are paying them 2+% to hold 40% big 5 Canadian banks!!