Simply due to the fact that most power management profiles for battery include dimmed display and blanked display after non-use, even sleep mode after very short periods. To get a fair test, the units would need to be identical hardware and have users simultaneously making identical inputs to the computers.

Which brings up the question, are they using the computers during this time and to what level? Are they using the gee whiz graphic features of 7 constantly during the time frame?

The one gripe I have with my new laptop, when I close the lid and put it to sleep it does not recover the wireless connection on waking. I end up having to boot the computer and reset the wireless router to get a connection. What then, is the point of sleeping? Might as well shut it down. 7 boots fast enough that it is not an issue like it was with xp, vista.