Fast, functional and beautiful.

I used a Sony Walkman Live before.

The positives of the Lumia to me:

What impresses me about what Lumia is fluidity, either internet, music, or videos. I love the simplicity of Windows 8.1 configuration options are less comprehensive than Android, but he who seeks primarily a phone call and surf the internet if needed will be quite satisfied. Grand bonus: The navi (Here drive) integrated.

J looked a film about the nokia and J stays satisfied with the quality of the image.
The camera starts up quickly, in less than 20 seconds it is ready.

I had problems accessing services goggle at first, but after an update of Windows Phone everything worked.

Little surprise: there was a headset in the box, so a more compared to 630.
Connected to a computer with linux gsm functions as a USB key. Not tested on windows.

Minor drawbacks: for an update must be connected to a Wifi network, the device refuses updates on the 3 or 4G network. This problem, however, disappeared after a lay-Day.
The rotation of the screen is sometimes a bit slow.
The Mix Radio service is not yet disponble Belgium.
The presentation configurations more like a long list that a real menu.
Sometimes you have to wait a bit to switch between applications. This is probably due to the 512 mb of ram.

For the rest I think everything is said in the reviews of the 630, which is the same model without 4G.