Quote from TILT2:
How about CFD(contract for difference for dow jones index and s&p500 index)?
What do you think the answer is going to be?
CFDs often just add leverage, increase the financing charges for holding over rollover, and increase the total spread / cost per trade over the securities or futures they track (since the broker needs to pad the spread a bit over what they hedge positions against in the underlying futures market.
An inappropriate use of leverage plus unrealistic expectations will kill your account pretty quickly, and increasing the total cost of trading through a padded spread doesn't help either.