Depends on your usage, with light usage it might reach 24 hours, but generally you are looking at 12 to 20 hours. Again it really depends on your usage. If you are really concerned about the battery life, as I am, I suggest waiting a few days to observe early adapters feedback and reviewers who had the product for few days. Keep an eye on MKBHD review coming very soon. Generally batteries will yield better results after few cycle.
Here is Motorola declaimer about the 1 day claim: All battery life claims are approximate and based on an average user profile that includes both usage and standby. Battery performance depends on network configuration, signal strength, operating temperature, features selected, and voice, data and other applications usage patterns.