I've got the latest update - ICS and the post-ICS update. I occasionally measure power consumption during sleep overnight. Pre-ICS (Android 3.2.1) it was 1.5 - 2% per hour. I rooted and modified build.prop to make it sleep deeper, and it dropped to just under 1% per hour.
Fast forward to ICS. Now it consumes 2+% per hour during sleep. After I rooted and modified build.prop to make it sleep deeper (same settings as Android 3), it consumes 1 - 1.5% per hour.
In short, Android 4 consumes more battery during sleep than Android 3 did. The battery screen doesn't identify any offending app, just shows up under "tablet idle".
It's not bad enough to be a problem, but a bit disappointing especially given the A100's wimpy battery.
Note: the build.prop settings are:
Any other settings I can use to improve things?
I've been having similar problems. And once in a while I install an app that won't ever let the tablet actually sleep. HD widgets was horrible. The wifi never shut off. I installed auto airplane mode from google play. When the screen is off there in no wifi. It works great. really increased my overall battery life. Only downside it that you have to turn the app off if you want to stream music with the screen off.
Just tested again last night. Tablet asleep for 8 hours, consumed 6% battery. Looks like it's back to < 1% per hour. And that's with no changes to build.prop.
But, Google Maps still consumes battery even when not being used, so I used Titanium Backup to freeze it. I never used it anyway, as Earth and Sygic together do everything Maps did, and much better.
My tablet recently bricked and I had to restore it from scratch. Looks like there was some benefit to reloading clean after 10+ months of heavy use.