Yep, I can speak as a very addicted smoker - I used Chantix, it worked wonderfully & I personally experienced no side effects - I was able to easily quit & stayed quit for 4 months (after many years of smoking and many failed attempts with patches, gum, cold turkey, that lasted no more than a few days)
I fell off the wagon though due to a stressful time with a serious illness in the family. When I get myself ready to quit again it'll be with Chantix. Costs about $100 to $125 a month (about the same as cigs for me)
I don't know that everyone might have the same experience I did (different personality, addiction, biology) but I highly recommend giving it a try.