Hi Lakitu, not really sure of the ins and outs but my ex-husband used this and managed to give up on it, quite easily - didn't have many side effects that I can remember (think he had a headache for the first fews days or something, nothing major).
I think the idea is you have 1 a day and are still allowed to smoke (correct me if i'm wrong) then you take two, therefore and have no cigs and after a day or so of that, your need gradually reduces it.
Having said that, my husband did end up going back to smoking, although a fair while after using the tablet, but to be honest, I don't think he really wanted to give up at the time anyway.
As for the horror stories - that really scared me when he first talked about using it but he was convinced he'd be fine and he was. Defintiely a minority I think.
Good luck!!!