I personally don't like using these machines... Yes they're efficient, and yes they have worked fine everytime I've used them, and no, I have no actual problems using them per se, but...
It distances you from the experience, from the airline itself. Even OLCI does this and whilst useful to select your seats and the like, I still in the end like to go down to the desk, check my bags in chat with the person checking me in, and receive my tickets in hand from "a person".
Oh well... anything to cut costs I guess.