I have 2 GP100's just alike in 357mag one with the two hole port the other with the four hole port... I can't tell enough difference between them that I would pay the additional cost again. That's just my thought. I sent them off at different times. I could tell a difference between ported and non ported. I am not sure I would go to the expense to do another 357. I think barrel length, scoped or not, type of loads, etc. Would influence my action.