I've watched people exit the 2x2s for decades now, and there definitely are some trends about exiting which have become apparent. I'd like to share what I have learned from watching this process, maybe it will help someone.

The most obvious is the Christian versus non-Christian split.  Some folks figure out that 2x2ism is a heretical sect and try to find out what actual Christianity is by joining another church.  The second group falsely believes that 2x2ism is representative of Christianity, and since 2x2ism is false, then Christianity is false.

Within the folks who move from the 2x2 church to another church, there are four basic layers of the onion they may or may not peel back in their journey.  The first layer of the onion is the exclusivity layer.  This hurdle of accepting that there might be other 'saved' people in the world other than 2x2s is generally the first step to considering that another church might be acceptable.  Does this mean that the reformed 2x2 is in communion with all other Christians? No, because exclusivity is only one of many heresies that the 2x2 has embedded in her mind. Upon leaving the exclusivity orbit, the reformed 2x2 will likely consider fundamentalist churches a good fit for her.  So, various strains of Baptists, Church of Christ, Pentecostal, and many non-denominational places. 

When the reformed 2x2 peels back the second layer of her 2x2 indoctrination, she will realize that not only was she in an exclusivitist sect, but also in a Fundamentalist sect. Yes, Fundamentalism is a very extreme variant of Christianity, extreme in that it takes the Old Testament to be literally and historically true.  This is not what the vast majority of Christians believe nor is it what any Christian scholars believe (other than quacks). Fundamentalists are a small percentage of Christians, and are almost exclusivity concentrated in the USA and a few other English-speaking countries, though recent years have been making headway among other uneducated peoples in developing countries.  This is sad because Fundamentalism is generally also what the ex-2x2er who becomes an atheist is actually opposed to, but doesn't know it.  By removing the Fundamentalist layer of the onion, the reformed 2x2 will explore such churches as Methodist, Congregationalist, United Church of Canada, Presbyterians, Dutch Reformed, other Calvinist churches, and some strains of Baptists. This will put the reformed 2x2 in communion with about 25% of the world's Christians

The third layer of 2x2 indoctrination is a much bigger big leap to see and ultimately peel back.  This is the layer of anti-liturgicalism, sometimes referred to as  Calvinism.   The anti-liturgical strain makes reformed 2x2s stay clear of any church which has any adornments inside the church, any vestments on the clergy, any prescribed structure to the worship service.  Very few reformed 2x2s can get over this hurdle because of their indoctrination of needing to be in a 'restorative' early New Testament church.  For them, restorative means simplicity in all things, Puritanical. If the reformed 2x2 can see the folly of this hurdle, she will explore such liturgical churches such as Anglican, Lutheran, Church of Sweden, Eastern Orthodox, etc.  With this move, the reformed 2x2 will now be in communion with about 50% of the world's Christians. It may be helpful for the ex-2x2 to read the writings of the Early Church fathers who were writing contemporaneously when the New Testament was being written.  

The final layer of the onion of 2x2 indoctrination to peel back is the anti-Catholic layer. Given that 2x2ism was started in Northern Ireland, it should be no surprise that it is a virulently anti-Catholic sect.  There are various forms of Catholicism, to which the reformed 2x2 is likely not even aware of, as the reformed 2x2's major mental roadblock is the Roman Catholic (aka Latin) Church - the one headquartered in Vatican City. The reformed 2x2 has a litany of reasons to support her anti-Catholicism, but all of them are strawman arguments based on misunderstanding or fabrications - no different than the other Fundamentalist and Calvinist critiques of the Latin Church. It may help to read Karl Keating’s book. By removing this final layer of indoctrination and recognizing that Roman Catholics are legitimate Christians, the reformed 2x2 will have now included the remaining 50% of Christians into her communion. 

It's very important for 2x2s who begin their de-programming process to understand that they are/were in a Restorative Fundamentalist Protestant exclusivist sect. It's layers of heresy, and it needs to be unwound.  Christianity is a house with many different rooms, each room has different styles of worship.  Do not stay in the hallways, you must go into the room. And if a room has a closed door, then it might not be part of the house.