YouTube's earning is closed to final earning you're going to get because YouTube shows estimated earning after adsense's cut and YouTube's cut, not only that YouTube has it's 'reserved' ad system, which is not from adword auction based, as YouTube says it, simply it means those ads are not from AdSense. You can even check how much you've made from non adword (take it as AdSense) based ads which can be both display or overlay ads.
And ya tracking AdSense reporting is charming and informative at the same time, I always got an idea that my video views picking up or down, but it's not exact realtime, I think it's 1-2 hours late.