My experience has been pretty solid other than having to wait nearly a year for that Anniversary Infidel but once I found out why I was willing to wait. No issues with the handful or so Infidels I've personally owned. I don't go out of my to try to break my knives or abuse them though so not sure how typical my use is. I'm carrying a Microtech Ultratech currently because it disappears in my pocket as compared to the Infidel. The mini-Infidel is a real good size as well. They also have a Pagan model which I have limited first-hand experience with as I haven't owned one.
If you're on a budget I'd say to also check out the Precipice. I have a buddy who got one last year from GOVX or one of those first responder sites pretty cheap and he's had really good luck with it as well. It fires from the side like a Microtech and he's liked his. It's more of an entry-level version though so if you're looking for the most reliable, not sure how that one will stack up long-term. It's still a multi-hundred dollar knife though so I would imagine it's going to be hold up. I just don't have any long-term intel on that particular model to offer up.