I'm looking to equip my Gen4 G21 with an internal laser but do not have a lot of knowledge of their efficiency and durability. The only brand I can seem to find research on is LaserMax, but have come across a lot of bad reviews. What are y'all thoughts/opinions/complaints/praises for guide rod lasers? What brands do you recommend? What brands should I stay away from? Wanna kill these ads? We can help!