I bought a the great Samsung galaxy S duos 2. it has 700MB ram , 4GB rom and 5MP rear camera. starting it is nice smartphone good performance, after 1 year it starts little hanging and sometimes strucks and after few months, It is acting like hanging specialist and I prefer the hard data reset then 2 to 3 days goes normally and then starts hanging.lastly I goto the service center and they updated jelly bean to kit Kat Android version but it is not stopped hanging. now in that only one third-party app that is whatsapp but now also opening of app is slow and sometimes strucks I don’t see the this type of irritating phone I don’t know why it is happening mostly the hardware parts are low qualities.