as others have said...it takesa couple of days for the battery to settle down. Give it some time. Yesturday i spent 2 hours on Pandora at the gym another hour playing music through bluetooth on my truck and 30 texts and about 30 minutes of emails. Took it off the charger at 5Am and at 7Pm it was at 42% so that is not too bad. Plus the phone is new so I am spednig a lot of time goign through the menus and getting aquainted with it!
Plus showing it off to friends and co workers and taking 15 pictures to demo the camera.....not bad!
5-6 hours of screen time seemed standard according to users on XDA. As for battery calibration, it's a myth or HTC does not calibrate it's batteries before shipping their devices which is unlikely these days.