HTC Windows Phone 8X vs Nokia Lumia 820. Help me decide.

Hi, I'm due a upgrade of my current smartphone the iPhone 3GS and want to get a Windows Phone.

In my country (Ireland) the only available handsets are The Windows Phone 8X and 8S. The Lumia 820 is available on the 1st of Feb 2013 so pretty soon ( No sign of 920 yet, if there is i'll get that )

I've looked at the specs and all I can see in major differences is that the Lumia has 8GB storage and the HTC has 16 but the Lumia has a microSD card slot to expand. There both have the same amount of RAM and processor.

What confuses me is how the Lumia 820 is referred to as a "Mid Range" device and the HTC 8X is referred to as "High end"

Anyone own either or device? Pro's, Con's? Something i'm missing?