legacy: There are no extra charges that I know of. I trade with Schwab and just to be sure, I looked at the eConfirm and saw only the normal commission. I would recommend a call to your broker to confirm that your brokerage does the same as Schwab.
You can tripple you money every year buy going back and fourth between QID and QLD, holding for a few weeks to a couple months at time depending on what the market is doing, and by looking at their charts.