Cooltrader...
One other study I did you might find interesting...
I compared the fills in the big Nasdaq and the e-mini. The study was conducted by repeatedly entering market orders for 5 e-minis and 1 large Nasdaq at the same time. I alternated which one got entered first and they both got entered within seconds of each other.
For the emini's, of course, I had the fills within a second.
For the large Nasdaq's I had an online TOPS direct access to the Mann Financial traders on the floor. I would get my fills back in 5 to 15 minutes after someone entered them in the online system.
The result was that you get better fills in the e-mini with 95% confidence.
Of course it took a little longer to get the trades done via the pit, but you would expect that, due to the small delay, sometimes you would get a better price and sometimes a worse price as the market moved in those seconds. That was true, but _on average_ the price was worse in the big Nasdaq's. Now, no matter how many contracts I want to put on, I use the e-mini's.
Aaron Schindler
Schindler Trading