Nokia Lumia 625 vs Nokia Lumia 820, which one should I buy?

Hi all,

I'm a long-time Windows Phone user and I've had an HTC HD7 since early 2011 and I feel like it's time to upgrade. So, since I just dropped $500 on an Xbox One I don't want to spend more than $250 on a phone (budgets and bills..etc). I can't decide whether to get an 820 or 625.

Both devices have comparable specs, and I'm fine with either size but the 820 is a year older and has a smaller battery(1650 mAh) while the 625 was just released last month, has a bigger battery(2000mAh) and a Gorilla Glass 2 display. At the same time, I want to go with the 820 since it has more RAM/Faster CPU and supports NFC and Wi-Fi Direct.

Any help is appreciated.

GSMArena comparison http://www.gsmarena.com/compare.php3?idPhone1=4968&idPhone2=5438