I quite smokiing June 20th of 2010. I used Chantix without any issues and actually stopped using the Chantix after 3 months because I didn't feel the need for it anymore. I was a 2 1/2 pack a day smoker for 16 years.
Now I will say I replaced my addiction with more physical persuits. I do Taekwondo, Shurkin Ryu, Brazilian jujitsu, weight lifting, jogging, and ball room dancing. If I don't get some physical excersise in for at least 1 hour and preferably 2 hours a day I get really antsy. The way I look at it though is at least my addictions are good for me now!