I hav used Sony Xperia P(4.0 ICS) for 6 months. At 1st, it was very fast & smooth, but after 2 months of use it started hanging a LOT.I used 16gb full of songs,videos,photos & also downloaded many apps but then even low graphic games like angry bird started hanging which made me very angry :P Now i have sold this phone in a 2nd hand phone market & promised never to buy a android phone ever.I also heard that such hanging problems r not there with WP8 & ios phones.Also one of my friend bought L920 & it was amazing to use.Cant afford a 920 but i went for Lumia720, i hope it will be as good as 920! :) Pls note: 1GB RAM in Android=512MB RAM on WP8 Enjoy!!!

Siva, you are absolutely right, because i use Xperia Sola and other android phone same problem. Now i am purchase Lumia 620 & 520 best mobile so smooth and faster than android, But some hanging problem in all smart phone.