I think it's more of a personal preference than anything. I have several Glocks and the stock sights work fine for me. I do prefer the nightsights though. I've tried guns with many aftermarket sights on them and have found them very useful, but not enough for me to spend that much money to replace my adequate stock sights. I'd try out as many different sights as you can at the class and make the decision for yourself what you like and if it's worth replacing your factory sights.