I just bought that handset. And using it from a month. I am very satisfied with that android device but I still think that need to be fix some of the bugs.
DISPLAY: I love the dispay quality they provided. The display is corning gorilla glass 3 in 5.5 inch size. And the touch is very smooth and responsive. And that display makes the phone very classy and beautiful. The colour of the contents are very vivid and attractive.
CAMERA: the back camera is 13 MP and the front camera is 5 megapixel. Back camera is really very good and takes beautiful pictures. This handset has very good dual led flash. So even during night it captures good photographs. The front camera is average. After taking pictures. It makes the pictures a little dull and unclear. But it is quite good.
WEIGHT AND LOOK: the weight of this device is good. And this handset look like oneplus one. This is not a very slim one. But still it looks very decent in black colour. It has dual led flash with camera and fingerprint scanner back side with dolby and lenovo marking anf it has volume and power button in silver pannel at right side. Silver pannels make this model very beautiful.
MEMORY: it has 16 gb internal memory and you can expand it by adding external memory card. But system takes very much memory. So there may be some memory issue in future. There is 3 gb powerfull ram. So the multitasking and gaming is very smooth. 3 gb ram attracts the customers.
BATTERY: I like the battery capacity of that device. It has 3300 mah li-po battery which is non-removable. And the phone charging is also very fast. The battery easily works for full day even continously in wi-fi.
SOUND: I love the sound provided by dolby. It is louder but very decent. And it is a really good one.
PROCESSOR: IT has 1.3 GHZ octacore processor. It is quite good.
SPECIAL FEATURES: it comea with theatermax technology. There is a special feauture in phone. By pressing VR mode your display will split into 2 and with that you can enjoy theater experiance with your device. But for that you have to buy lenovo compatible VR BUNDLE separately. There are additional fingerprint sensor and gyroscope. Some of the gestures are also additional.
COMMON FEATURES: it has dual 4g sim capacity. And it has fm radio, gps, wifi and also has android 5.1.1 lollipop operating system.
In short it is a budget phone with power loaded features. I think you should but it if they fix up some bugs described in my cons description.
CONS: in spite of having 3 gb ram the phone hangs many time. So I have to restart the phone during that occasions. The battery is non-removable and the ram is 3 gb so due to functional excess the front speaker pannel hits a lot many time. The hitting problem is the bigger disadvantage of that device.
And the proximity sensor of that device also had much bugs. It does not works properly in many of k4 note device. Similar handsets like redmi note 3 and letv devices provide less price and 32 gb internal memory. So the memory of comparative devices is higher than that.
The lenovo service is not that of good. The service centers are always busy. It is difficult to talk with customer care representatives.
And in that device except theatermax technology and fingerprint sensor they did not do much work in enhancing the performance and fixing the bugs.