Maggie, I think you need to decide what you are comfortable with. DS#1 used to fall asleep on me a lot of the time but has always been able to settle himself to sleep anyway. But this is probably not true of all bubs. So the short answer to your question is it might be creating a habit that you will have trouble breaking, or it might not. I guess you need to weigh up what is going to work for you, and how much of a problem it will be if DS is not able to self-settle later. Unfortunately there is usually no easy answer!!