The only experience I have is with their triggers. They make very nice triggers and I would love to have one for each of my Glocks. There is also another company that makes triggers just like the Zev which I believe are a little cheaper, but I can't recall the company. As far as the rest, I personally don't see the point, but it's an individual taste thing. My preference with a Glock would be upgrade the trigger and sights and leave the rest.