I've dated two christians and a muslim.
For me, it's okay as long as they can bring philosophy to the conversation. When talking about religion, I prefer to leave my 'Gods don't exist period!' at the door, and hope the other party does the same with their 'God omgz!'. Failing that, I don't see how a conversation on this subject can be held, but what I feel mostly is that religious people will somehow think less of me for being an atheist, rather than me thinking less of them for being deist. After all; in my eyes, there is no such thing as sin, while in their eyes, I am a sinner.