After two weeks of (im)patiently waiting, my extended battery has arrived.
First thing first, it is HUGE. The battery cover probably adds 30-40% to the thickness of the phone. I switched the battery in about 6 hours ago, currently at 70ish% after 12 hours. Going to do a full charge over night, clear the battery stats and see how it lasts through the day.
EDIT: 7.5 hours later, currently at 85%. Been using WiFi for data all day just been checking emails/small amounts of browsing.