I sleep much much better without a clock in the room. I've always been a naturally early riser but I do sometimes have trouble falling asleep.
When my first child was born, I always checked the clock when she woke up during the night. Every day, I could tell you her sleep schedule the night before.
I found myself thinking about it WAY too much (wondering how to reduce the nightwaking, worrying whether it would affect me the next day, etc). Now my 2nd baby, I've gotten rid of the clock and I don't become anxious when he wakes me in the night. I feed him, snuggle a bit and go right back to sleep. We all still wake up at dawn but I feel much more relaxed and rested.