[Portability]
Because my previous model was of 4.5 inches, I thought that 5.2 inches size was rather big at the start , but I grew accustomed to it naturally while using it.
I think that the portability is rather good because the main body is thin and light.
I may not return to the small size again, perhaps.

[Button Operation]
There is a slightly disappointing thing as to this respect.
The power button and volume button are both located in the middle of the right side of the phone, so many times when I pick the device up, or when I slide it in the pocket of my pants, I accidentally touch the power button, and consequently the volume button too. This causes the vibrate mode to be switched on and off without my knowledge, in many occasions.
My finger hits it, naturally.
Well, maybe the only thing I can do about this is getting used.

[Response]
Wonderful. Smooth, with barely no freezing.

[Menu]
There is a home app that I have been using from early on, so I will not evaluate this.
[Screen Display]
Extremely clear.
I suppose that it is too much to demand further clarity at the present time?

[Call Quality]
I do not feel any stress at all with its clear sound quality.

[Ringtone/Music]
Because I am a Walkman fan and user, no evaluation as to the music, but the ringtone plays nice sound.

[Battery]
The heavy users may demand more, but for me I am satisfied with it because around 70% of the battery I charge fully in the morning remains after several minutes' calls, sending several emails and internet browsing of around 30 minutes during weekdays.
Only I feel uneasy because I cannot remove the battery, but I hope that I may use the stamina mode well and efficiently so that I will be able to use the terminal for a long time.
-------Review by an Japanese anonymous on Jul 6, 2015 --------

- In Indonesia, Sony faced some labor unrest thus affecting its output.
-  In Britain and Mexico, similar cases of labor unrest and issues have been faced and the reason there is need to address them.
- The presented analysis shows that Sony is facing challenges in finding the best talent for its organizational operations in Europe and China.
- Workforce diversity is one of Sony's challenges. Even marketing and catering for the product on different markets and after sales are the challenges that the company needs to work on.

- According to the 2007 annual report of Sony. The challenge is in planning and managing operations due to unfavorable political economic factors; instability in the Middle East from war, cultural-religious conflicts, foreign exchange controls/unexpected controls, nationalization of assets or restrictions on the repatriation of returns from foreign investments.

- The subordinates cannot fully understand the message / opinion that the superior wants to convey due to the language barriers. This makes productivity inefficient.
- When working with foreign partners, the lack of knowledge about the partners' culture and language barriers also makes the negotiation process lengthen as well as leading to conflicts between the two parties. Ultimately, cooperation will become difficult and sometimes impossible to conclude.