I'd be curious on "over rated" in what way? Performance? Durability? Cam Break-in procedure? Running basic oils that are common and not high in zinc? Not arguing, but curious on your thoughts? Cost is about the only thing I can think of where a flat tappet cam has the advantage over a roller.
Over rated mostly because people put the flat tappet down for the wrong reasons. No doubt the roller is superior in most cases. I just think people get hung up on it for the wrong reasons. I sure would not let it sway me on a block decision.