Which is better? Nokia Lumia 620 or Nokia Lumia 520?

I'm trying decide which is overall better between the two Nokia Lumia models, I just need a phone which makes calls and texts (well, duh), has wi-fi so I can use Facebook, youtube, browse the web and the occasional Xbox/Windows Phone game and has a decent camera and Nokia seems to be in my price limit, before I get the "Get the iPhone/Android Phone/Sony, etc" answers, don't even bother, I've been hearing good things about Nokia, I like the Windows 8 design, and I just want to know which model is better between the Lumia 620 and Lumia 520, Thanks
- Dan

Hey budy 620 is better than 520
More Ram more battery more speed

Lumia 620 better but i love 520

I have Lumia 620 and it's ok but Windows 8 has many problems

It lacks some basic features like:
No file manager or explorer available
You can't install any application on memory card
You can't know the duration of any old phone call