I'm in my 4th year residency at a well known hospital in Chicago. Being an up and comming anesthesiologist, I've dealt with 13 lung transplant patients pre and post op.
From what I've seen, it makes an incredible difference in the quality of life. The severity of the cases varied, but just talking to the patient, I could see that his/her personality changed(for the better) quite a bit.
If you're a little skeptical about whether or not you should go through with the surgery, my honest opinion, from experience, is that it is worth it.
Lung transplant does have its risks, just like any other type of surgery, but compared to other types of transplants, it is minimal. Assuming you are a good candidate for the procedure, it can only benefit you. The real question you should ask yourself is "why not?"
Just my personal encounters with this treatment. Hope it helped.