I found something worth sharing for us permanently battery and resource thirsty.
I recently upgrade my Note 2 (N7105) to Stock KitKat 4.4.2 and immediately started checking the battery performance, which is quite impressive.
I have been using on 4.3 the TouchWiz Launcher but tried the Apex launcher on 4.4.2 battery performance went down significantly.
with Apex I managed to get barely 18 hours battery with normal use.
I have decided to test both touchwiz and apex with the same desktops (apps and widgets) over a single night without use.
the test with Apex led to a battery loss of 30%
the test with TouchWIz led to a battery loss of 7%
until I will find a better solution, I will stay with TouchWIz.