On the other hand, the sessions I attend seem to work really well. I get an appointment, and I'm usually sat down bleeding within 5 mins of the time. However there do seem to be plenty of "drop-ins" turning up, and from what I've seen no-one has to hang about for long. Admittedly this may be because of the more rural location/lower numbers..
I suspect the appointment system is successful because it serves as a convenient reminder, I get a letter a week before my next app confirming time and simply turn up. Oh and I cant say I've ever been made to feel like a "commodity" when giving blood.
I do occasionally get a letter asking me to switch to being a platelet donor (AB+ blood is universal platelet donor) but this would involve a 4hr trip to Bradford up to every 2 weeks.... my altruism doesn't stretch that far unfortunately.