My first try, i tried for 1 week and it was getting worse and worse (no real improvements) so I quit in favor of Gradual Withdrawal.
Second try, ds was 18 months and it went all smooth and easy at exactly 20 days. It was like magic, I was about to give in and that very day we turned a corner. I had already (like you) seen improvements for the previous 20 days but other days were AWFUL. Mostly when I thought it was already solved, we had 2 steps back for a couple of days but on day 20 it was all uphill. Even now, when there's an illness, a particularly stressful day (you know that type when they throw a lot of tantrums and there are tears all day long), etc... we have to go there and try it again for naps or bedtime but it doesn't take more than 2 days. I know some days at night I feel so guilty at just walking out of the door and never look back! i was so used to stay in the darkness for over a year that i never thought my day would come.
Just keep up the good job, because eventually it pays off!!!!!! oh it's sooooooo good!!!!!!