Well speaking about lumia 520 the best thing was about its sleek and stylish look. 520 is very cheap approx 10, 000 rs in Indian market. It has dual core 1GHz processor with 400mb RAM thanks to WP8 very less memory footprint apps can run very smoothly.
Its display as very touch sensitive. The camera is very OK but cant expect much from the windows most cheapest mobile. The best part of the lumia 520 is its email application can send email and receive it instantly, best for business use.
Wp8 has Facebook integrated in it, so you can see all the notifications instantly. Nokia also provide Nokia music app its really a great app as you can download many copyrighted songs for free, THAT’s GREAT for the guy who loves Bollywood music.
The only biggest let down is the app store which has very few good and free app, most of the app are paid. Its a very good smartphone from Nokia and a great replacement for android who all has got bored from the OS.