I grew up in this religion, I was baptized at 14, married at 27, and now I'm 31. I'm also evolutionist and atheist. I wanted this to be the truth. I spent years as an apologist trying to reconcile everything. Nope. You really can't do it, and as you see all the flaws, it just becomes a rotten experience to go to the meeting.
I've read The God Delusion and 30 Years a Watchtower Slave (hence my username) among other books. My family wants me to stay, and my friends want me to stay, and everyone who sees me just knows that that I haven't been to meetings and they ask "Are you okay?"
Frankly, I'm tired of being asked if I'm okay. I'm good, it's the religion you're preaching that you should be looking at.
So now I'm considering writing my letter and making it official. The benefit is simply that people in this cult will finally leave me alone, except possibly for the elders. I'll deal with them. They can bring it, because creationism and Bible literalism and prophecy cannot stand up to science and Bible criticism.
As with seemingly every atheist, I pursued the truth, and the truth set me free. Thanks everyone.