I wasn't making the point that $5 is better or worse. I said trading fees could double during the move to the CME.
If you want to discuss if the move to $5 is better or not, i have to say overall is it worse. I think the daily notional volume that is trading after the switch from $10 to $5 is lower than perviously. ie halving the value of the contract hasn't doubled the volume. This means the change as weakened this particular futures market.
Also i noticed market depth did not double after the change, so again the market seems weaker to me. This could lead to more slippage under fast market conditions.