Every gun I own is Mag-Na-Ported; Currently that is 5 carry revolver's, but I am adding a Sig Sauer 1911 that will immediately be sent off for Auto-Porting from the same firm. Not one gun did I ever notice a limited or non existent improvement over the non ported version. The only notice of any kind worth mentioning is with my model 60 and its milled in front sight blade, after shooting a bunch of lead ammo, I did notice some lead exposure to the sides of the front sight blade. Easily cleaned off with some Hoppe's #9. And for the average Joe firearm, the end result of porting is the increase of value for the gun. Sure, a prime example of a Colt SSA in 44-40 might suffer financially if it were to be ported, but certainly not your every day service revolver or auto. Mag-Na-Port does excellent work and it's worth every penny spent on the addition. Smithy.
Salvation is through our Lord and Savior Jesus Christ and in Him alone.