I've only been banded for less than a week so I cant give a full perspective but I will do my best. My biggest problem was when I came home. I had so much swelling, a slight respiratory infection, a long walk to the house and then the living room was extremely dry. After 15 minutes, I had to go for my inhaler. That was the only time I had a problem.
It's going to be uncomfortable to breathe deeply initially, but that goes after two to three days later. Today (5 days post op), my lungs feel pretty darn good! My swelling is down and I am much more comfortable walking around. In fact, I walked around the block this afternoon (needless to say, I didnt break any land speed records).
A friend of mine who has asthma and had the full bypass done said that his asthma is much more manageable since he had his surgery. He's almost 2 years post op. He completed the couch to 5k program and loves to run (he just keeps his inhaler nearby). I'm planning on starting that as soon as I drop enough weight that it won't punish my knees too much.