I quit on this past New Year's Day.  Cold turkey.  I haven't had any real cravings past the first couple of days.  I feel great. I started smoking at 21 and now at 51 it's been way too long.  I quit for 8 months a few years ago - this time I feel I am ready.  I look forward to healthier days, fresher air, some new PRs (it could happen), and a clearer head.