I have two now and have had one of them for about twenty years now. I have never had an issue with them and have fed all kinds of ammo thru them. Can't remember the last time I gave them a real good cleaning, just a wipe down and back at it. As for reliability, I would say glock is the pistol...
I work in the medical device industry and we machine pieces made with this process on a daily basis. We have found that these pieces are as strong as and lighter than using solid pieces of material. Very interesting process to see.
There is a good article on the front page of Wednesday's USA Today. It deals with the gun manufacturers located in the NE of the country, with a pic of the CEO of Stag Arms holding an AR. Good reading