i cannot confirm this either.
though i have to admit i never used my device before the update.
when i first got my device 2 days ago, i turned it on, set up the wlan and the first thing i did was download and install the update.

but aside from that, when my device is idling, the cpu-usage-meter shows 1 bar (the bottom grey one) that propably indicated that the device is basically doing nothing.

2 days ago i went to sleep at 1 am in the morning when the battery-bar showed around 20% energy left.
i woke up at 12 o clock and to my surprise the device didnt turn off as i expected, but still showed around 10% or so battery left.