People's opinions on the crankcase ventilation system is irrelevant. On a Mass air flow metered engine you must keep the PCV valve, hoses, and breather pipes all connected AFTER the MAF sensor. All the combustion blow by gasses is previously metered air and thus it will not affect the runability of the motor. If you want to open the breather vent tube to the atmosphere, then you must also remove the PCV hose from intake manifold. This eliminates the entire crankcase from the intake tract and any modifications will not effect engine runability/driveability.
However, disabling the PCV system does nothing good. Keeping the crankcase vented has many benefits. Yes there are HP gains in this as well. On well modified motors, there are large gains to be had. I myself have seen 20-30whp on DET motors making 500whp.
-Ted