I have auto sync turned on and keep the screen low when possible. I NEED auto sync on because of the nature of my work. Compared to my iPhone 4S battery is downright pathetic.
Today my usage consisted of one phone call, a few text messages, lots of Twitter, and light web browsing. Nothing too crazy. Again I'm being really conservative with my usage whereas on my iPhone I can do whatever I want and not worry. I'm just not seeing how people are getting 15+ hours and claim heavy usage. I'd love to believe that! The battery drains so fast during normal usage it may be a deal breaker for me.
Edit: My battery discharged 2% just while writing this post.
Sent from my Galaxy Nexus using XDA App