I have tried to time the simulator for real time and have found that the exchange that the equity is on can make a difference in delay time. I noticed so far that AMEX is slowest (most delayed) then NASDAQ then NYSE. The stock itself can make a difference some times as well something like MSFT vs GNA. MSFT will execute very near the 20 min delay buy or sell where GNA may take up to 30 mins to execute.
I trade in Canadian Game and have found that the delays for TSE can be even worse. The problem is that the delays are not consistent enough to time them so if I see a real time quote and execute in the simulator on a fast mover it is a roll of the dice what the trade price will be.
The only real solution I have found is to go with sell limits and stop loss. This does not help with options contracts
Cheers