IMO - I just barely bought my first 'digital' and am making the switch off of 'analogs'. I myself am not worried about when or if I cough because I know I am making a healthier life choice and that is all that matters to me. Lung capacity will not change over night but I will be happy when I can play ball or jog for 2 miles like I used to. I mentally feel better already and the rest will come with patience.
Jay