I don't even know what a church Christian is, so I guess that pretty counts me out.
But I stopped believing in much of what the Watchtower taught while in the JW religion back in the 1990s before I left. I was only in for about 10 years. It started to unravel their teachings very quickly and easily.
Reading the Church Fathers made things fall apart for me. Also studying the way the Bible canon came about and learning the history of Marcion of Sinope, the inventor of the first Bible canon.
And I had already learned Hebrew from Hebrew school due to having Jewish parents before entering my first KH back in 1984 (10 years and I slept though paid attention to the whole thing, I swear), so that kind of destined me to a crash course ending with the JWs. (I remember the subject of my knowing Hebrew came to the attention to a young couple that I didn't know me too well, but one night they came to me out of the blue after a meeting and the husband said: "My wife and I had a family meeting and we decided we don't believe you know Hebrew. I thought you should know." And he turned around and walked away. Really weird. I'm like: שתוק, יא מטומטם!)
I don't think non-church or non-Bible Christians who left the Watchtower are going to give you the most interesting answers. I think the ones who are going to give you those are ones who are still stuck on believing that the Bible is where all belief must still come from.
People who are in the mainstream, even in mainstream religions, don't hold to a strong Bible-based view of the world or theology. So if someone leaves the Watchtower religion and is able to enter mainstream society, they of course aren't going to be holding any of the Watchtower's views whatsoever because no one in mainstream society does.
It is those who leave the JWs who still hold on to their NWT Bible or to the Bible as the source of focus, doctrine or truth that would be holding on to some of the doctrines of the Watchtower.