So, I have yet to fully test out the power, but I have some notes:
-Browser dims when loading pages to save battery (cool!)
-In the new launcher, there is no quick option to change your CPU settings.
-Playing Dead Trigger on the TF300T had less lag.
-When changing the options in Camera/Camcorder, the menu would stall a bit, wouldn't really call it lagging...
-More developer options
-I don't know if it's just me or if I need to test it more, but the ASUS Task Manager, when I lock whatever apps I want running, they somehow get unlocked and cleared out when I click on the clear button.
-Oddly enough today, my tablet was able to use the keyboard dock to log into my launcher, so disregard the last post about it.
So far, that's what I got, but I do have a to-do list:
-Figure out if the Bluetooth bug still persists
-Open other apps
-Enjoy the tablet like crazy and make people jealous of the 4.2 awesomeness.