If want to have less problem with the phone OS, I would suggest get the local set. The main reason is.......google play pre-installed without any issue to casual non-tech smartphone user. If get AP, they're using Mi-Store. For me its a big hassle for a casual user to install Google Play from Mi-store, then divert, etc. Get something that works straight from bootup. I know you might be able to install everything for her but its really your choice.
As for bugs, you think other brands no bugs kah! Even now, my S4 entire widgets will stop updating on screen and had to reboot every day or 2 to get it to work again (mobile data problem, everything activate/deactivate, it will have high chances of activating that bug).
I've gotten MI3 for both my wife and daughter. They loves it. Both of them keep mentioning it looks good and its super fast when surfing net thru Wi-Fi (better than my S4...of course lar, speed wise, cannot match anymore). I have not hear any issue on phone calls or sms from then so far, except that we have to put +6 in front of all contact numbers to ensure any sms comes in will show the contact name.
I don't know how long these phones will last but it looks to have decent makes, no better nor lousy than any other brands but at this price, I can get a replacement phone at a much shorter interval with upgraded specs rather than stay with a RM2K phone that have to last me much longer due to cost factor.
Wah, thanks for the reply. I will never buy any samsung shit cause I heard a lot of bad things about them. Ok, will definitely try my luck at local set.