Guys, I'm looking to buy a new smartphone, below are my specs :

Budget: Below RM500
Requirement:
-Mostly using it as a PDA : Calendar notes, GPS, chat (whatsapp), decent camera, some small office works, etc..
-Smaller the better, don't want hefty stuffs that's hard to fit in pockets.
-Very long battery life.
-Durable would be nice.

How well do you think the Redmi 1S meets them? I'm conflicted here on what to choose, this / Huawei's Honor 3C / Zenfone 5 (or 4).