To answer :
Battery Life is ok
GPS : Does not work outside of China. I guess it's more a software issue than an hardware issue.
Screen is quite good compare to my Iphone 3GS
3G and Wifi no problem at all.
This phone is good from an hardware point of view but really bad from a software point of view as Lenovo has its own layer on top of Android ICS and it's full of Chinese.
Any idea where can I find a ROW ROM for this mobile phone Lenovo S890 ?