I have been using this phone from last 15 days and problems facing are::-
1. Voice quality is worst, you will face disturbances coming when calling and talking with anyone.
2. you cannot call someone when you are on other call at the same time there is option to do that, niether there is any functionality for dialpad to change its settings for conference calling.
3. Lenovo customer support services are worst, I have called them on support number and they didn't even care they told me that we dont have service center in your city and can provide you with address of service center near your city.
I mean WTF, you have to leave your work and have to go out of town just for this repairing.
One thing I liked about is its customization lenovo did very well customization and haven't seen customization before in any other andriod phone.
My rating - 2 star [DO NOT PURCHASE]