I think it's a great thing - although I've never smoked and so can't fully empathise with smokers.
Simply too difficult to control/police. Don't forget the smoking ban is not in place to stop people smoking because they're in a pub/club per se, it's been put in place to stop people smoking primarily in the workplace....give the landlords freedom to choose,stipulate no smoking in food pubs,make pubs and clubs have extractors of a certain quality,etc.etc.