As I have seen there is no improvement in nokia and in smartphones nokia is a way back from other brands just due to lsck of features and a good operating system the phones of nokia are just sold because of its name no features and attractive things.
Asha 503 is a normal phone but not a smartphone very low quality of features and the opersting system is also very slow thats why I dont recommend nokia
Other smattphones are way better in the same price which have android and other features
