Sony has managed to achieve this feat and still keep the width down to 7.9mm and the weight to just 146gm, so you understand why we were so excited to get our hands on it. There are a choice of colours with white, purple and black options. T The Z carries forward the block-like design of previous generation Xperia and is completely flat from all sides with the exception of the corners and the edges being rounded off. It have 5 inch display.   There’s a microSIM, micro SD, micro USB and headphone jack, all well protected from dust and water.
                                                          There are a  13MP camera and an LED flash. Overall, the build and finish of the handset is very good and even a few drops left nothing more than minor scuff marks along the edge. Having said that, all’s not perfect with the Z. This was a little confusing since Sony says the glass is scratch proof.
                                    You get a 5-inch LCD panel with a 1920 x 1080p pixel density, giving you sharp text and images. While this sounds good on paper, the reality is quite different.Display is good.
                                          The Xperia Z is a quad-band GSM and 3G handset but no LTE support for India, at least in the current ROM. Along with this; you also get dual-band Wi-Fi, Bluetooth v4.0, NFC, GLONASS, the works basically. The GPS works well and is quick to triangulate your position. However, the phone heats up a lot when you use GPS, to a point where it’s uncomfortable to answer a call. 
The Z is fitted with a 2330mAh non-removable battery which managed two full loops in our video drain test and about 10-minutes into the third which racks up a grand total of 5-hours and 40-minutes. This poor performance is mainly due to the high-resolution screen. If the phone is used carefully under regular use, you can just about make it an entire day before having to charge it. 
                       So,I give a positive points to this device.My rating to this device is 7 out of 10.

                                  This  phone has a 3.5 inch display with 320 x 480 pixel resolution, that amounts to 165 ppi pixel density, and is not that attractive on a smartphone. In case of Rex 90, it does not seem bad as you hardly get to play games on this handset. Anyway, it's doubtful that anyone would love to watch videos on this handset.

                                          Samsung has implemented many features of smartphones in the Rex 90 to make it user friendly. Like that Rex 90 has a notification bar, which allows users to control WiFi, Bluetooth, and sound and flight modes. You can even access the music app from the notification bar. Besides, there is a provision to delete or place applications on the home page but in the menu page also .you can only arrange apps. 

                  The Samsung Rex 90 gives you GPRS/Edge connectivity. it means that you cannot have a 3G connection on this phone.Samsung Rex 90 comes with a 3.2 megapixel rear camera, and there is no front camera. The rear camera can be used for both video shooting as well as to capture still pictures. The camera app is like that as a Android camera app.

The launch of the Rex series of feature phones from Samsung to compete with the Nokia Asha series handsets. The Samsung Rex 90, on the other hand, performs slowly and does not look that good either.
                                         Rex battery is 1000 mah with 15hrs talktime.So, For this price I give a negative marks for this phone.