Muslims have a very childish view on the subject of conversion, one which consists of "People are converting so its better and true"
Ironically for all their boasting of people becoming muslim, they're the most insecure about people leaving islam, often punishing those who do and having a hissy fit over somebody who does leave Islam.
Also you cant get a true representation of conversion, when people who convert to Islam in the west get to boast and shout from the rooftops, while those who leave Islam in the Muslims world (and even Muslim communities in the west!!!) have to live in fear of punishment, wether official state sanctioned or un-official Mobs.
I abhor the concept of killing a person for leaving a religion. the Qur'an is quite clear there is to be no compulsion in religion. A person needs to be responsible only to God(swt) over their choice of religion. It is their own decision and they alone accept the result of the decision on judgement day.
Having been a Christian and now a Muslim, on a world wide basis, I do not see a person who leaves Islam as being in any more danger than a Christian who leaves Christianity. While typically "Christian Honor" killing are not called such I have found they do occur. Often called "Domestic Violence" with no further explanation. But I have found that it is not uncommon for a person who leaves Christianity in Italy, Spain, Greece and Portugal to become a victim of "Domestic Violence"
I know more than a few American Christians that have reverted to Islam and are afraid to have any family members know. It is one of the most common concerns I hear from recent converts to Islam.
Speaking as I Muslim.
I do not know who is a Muslim. No one does. That is only known to the person and Allaah(swt). None of us can see into another person's heart and thoughts. To be a Muslim it means a person is submitting to God(swt) to the best of their ability. If a person is Submitting to God(swt) they are Muslim even if they do not yet know they are Muslim.
Any one can claim to be a Muslim and not be one. Likewise there are probably people who claim not to be Muslim and are Muslims.
We do not know who is or who isn't a Muslim, we only know who claims to be.Muslim
I think the same goes for all religions. We do not know, we only know what a person claims to be.
Just my opinion I do not believe a person is any religion if they are not willing to say they are that religion, no matter what the consequences.
In other words:
A Christian is not a Christian If they are not willing to say they are Christian, no matter what the consequences.
A Jew is not a Jew If they are not willing to say they are Jewish, no matter what the consequences.
A Muslim is not a Muslim If they are not willing to say they are Muslim, no matter what the consequences.
etc
I think some Missionaries play the threat of death card to show the need of more Evangelizing. and to be able to claim higher converts than they actually have.
I was once a Missionary "converting" Muslims. In my ego I thought I had won more souls than the numbers showed, because I believed most converts were afraid to say they were Christian.