I just picked up a SP2022 9mm (great gun btw) and was looking for some knowledgeable input. Should I replace the polymer guide rod with a stainless steel one or leave it be? I've personally never heard of a guide rod failure and I understand some manufacturers engineer their products with consideration to the flex of the polymer. I also understand that in some cases the additional weight and rigidity of the stainless rods may be beneficial. I'm more concerned with longevity and durability. Thanks for your input.