Quote from falconview:
Option House, OPTIons Express and Thinkorswim comparisons
The only drawback to thinkorswim is the delayed data of 10 mins or so, they say is real time. Options Express do have real time data and that is their best point. Unfortunately their software is quirky. When you make out an order and change some parameters, it automatically goes back to default settings and if you dont re-check all your boxes for correct prices and contract numbers and strike prices, you can get screwed royally. One guy was complaining the delay in the cancell system on the software cost him $10,000. He was told he had a cancel and apparently did not. Somewhere along the line I may open a minimum account just to get their real time prices though.
Both Options Express and Options House and I am guessing here? Just an amateurs opinion, do FRONT RUNNING. When you put a limit order, it gets filled exactly at the limit price you entered, even if the price real time is .70 cents better than what you put. ThinkorSwim are better here. I often set limit orders due to their delayed data and get much better fills in real time, which please me no end. TOS seem to have delayed data in real time trading I�m finding of around 10 to 15 mins and in funny money trading of around 20 to 25 mins. It varies in delay.
All in all, in real time trading I�m finding TOS the best system, both for the bells and whistles and the better fills than I planned on.