I had no problems with chantix. Only nausea if I took it without food and occasional weird dreams. If you take it you are supposed to keep smoking while taking it. Eventually you will not feel the need to smoke, but if you do you will find it disgusting. It works.
They're really comfortable imo. They aren't as comfortable as a pair with a giant boost midsole, but I would consider them one of the more comfortable pairs I own.