Normal battery life for two-year-old iPad?

Question

My first iPad is nearly out of warranty.  According to the Apple store 'Genius' app (the little hand held device they seem to look at a great deal), my battery is "normal".
They couldn't define in real-world terms what "normal" was.  Does anyone know - is it five hours - eight hours (which would be close to the 80% rule listed here: http://www.apple.com/batteries/ipad.html)
Since I don't have the devices they use to measure "normal", what would you folks suggest as an argument starting-off point?
Here's what I did: pulled up CineXPlayer and looped a 60 minute TV show.  I left wi-fi ON, set brightness to auto, and turned the volume down to almost zero, since I wanted to sleep.
With this test, I will get nine hours before the iPad shuts down.
Would I get less if the volume was at say 75%?
Would I get more if the Wi-Fi was turned off?
How many hours at what concoction should be used as a standard for "normal"?
As much as I don't mind paying $99 sometime in the future for a fresh unit, if the battery is out of warrantied specs now, while my warranty is still active...well, that's the kind of Apple-care I would hope for.
PS - I HAVE updated to 5.1.1 and the latest firmware, restored the iPad to factory, then restored from my backup.
Cheers

Answer 1

During the warrranty coverage period, Apple will replace the battery if it drops below 50% of its original capacity. If it is out of warranty, Apple offers a battery replacement for $99, plus $6.95 shipping, subject to local tax.
The specs for the iPad 2 state that you can expect
Up to 10 hours of surfing the web on Wi-Fi, watching video, or listening to music
Up to 9 hours of surfing the web using cellular data network
The fine print on http://www.apple.com/ipad/ipad-2/specs.html says:
Testing conducted by Apple in February 2012 using preproduction iPad units and software. Testing consisted of full battery discharge while performing each of the following tasks: video playback, audio playback, and Internet browsing using Wi-Fi or cellular data network. Video content was a repeated 2-hour 23-minute movie purchased from the iTunes Store. Audio content was a playlist of 358 unique songs, consisting of a combination of songs imported from CDs using iTunes (128-Kbps AAC encoding) and songs purchased from the iTunes Store (256-Kbps AAC encoding). Internet over Wi-Fi and cellular data network tests were conducted using dedicated web and mail servers, browsing snapshot versions of 20 popular web pages, and receiving mail once an hour. All settings were default except: Wi-Fi was associated with a network (except for Internet browsing over cellular data network); the Wi-Fi feature Ask to Join Networks and Auto-Brightness were turned off. Battery life depends on device settings, usage, and many other factors. Battery tests are conducted using specific iPad units; actual results may vary.