Howdy folks, New member here. I have a S&W M&P 9mm full size (Gen 1) and a Shield 9mm (Gen1). I see a lot of people posting how the Gen 2 models are far superior. I don't know much about these models. Is there anything I should be concerned about with my gen 1 guns? Are they unreliable or do they have any issues that were resolved with Gen 2?