iPad 3 watching video: how much battery drainage to be expected?

I fully charged the battery using the wall 10W charger to 100% and left it on for another 20 minutes just to be sure, then started the movies immediately.

I tested both streamed web video thru netflix as well as a movie I loaded from iTunes and either way, I'd get a little under 6 hours of total battery life. This is based upon the observation that after 17 minutes into the film, the battery indicator decreased to 95%.

Just as a point of reference, I turned off all other applications, and kept the brightness at 2/3 of the way up, and volume at 1/4 of total output. The ipad is just 2-3 days old and I've barely used it until today. I also had a tech at the genius bar open the box when i bought it run some diagnostics to ensure it was working properly.

The battery usage is much slower surfing the web and doing other tasks like email, but the ipad is promoted at being usable for up to 10 hours on a full charge - is this about the same battery drain for others? I am guessing that the advertised 10 hours is for some video watching, and other, less intensive tasks mixed in...unless are you people getting 10 full hours of just watching videos?

If that's the case, then there is excessive battery drain on my unit.