Stock Glock to Gucci 2011: Is there a difference

We’ve all seen it. Shooters dumping thousands of dollars into their handgun, trying to chase performance. New trigger kits, tungsten rods, magwells, aluminum grips, high-end optics, and certainly more. However, does that money translate into practical performance? Are any of those upgrades truly needed for the average shooter, or is it purely a competition-focused arms race?