The problem is Windows Phone 7 was designed for much smaller WVGA AMOLED screens. With Windows Phone 8's support for a wide variety of specs including HD LCD displays, the apps that were good enough are now looking a little odd now. With the 1520, it is outrageously hard to use.
With GDR3, Microsoft gave devs a way to take advantage of the HD screen, called a zoombox control. That's how WPCentral looks so good on the 1520 right now.
The true support for 1080p apps comes with the WinRT framework, WinRT apps do look great on our 1520s. Try any of the new universal apps, they scale perfectly to the screen. Remote Desktop, Reading List, Torrex Pro, Files&Folders Pro, etc. Universal apps are the future, it is the type of update to look for in an app nowadays, because adding support for 8.1 doesn't cut it, that's just a workaround, universal apps have their built-in advantages over legacy apps that continue to get updates.