i have been using qcharts for about a year and a half.. you should be aware that qcharts level 2 screen does not show a crossed market.. if someone starts cranking a stock with isld or redi, you wont be able to see the true prices, just the highest bid .01 lower than the lowest ask.. also, my qcharts level 2 is slightly delayed compared to my level 2 feed from cyber.. if you are a swingtrader maybe it isnt such a big deal but if you daytrade, it can make a big difference.. =)
-qwik