The battery life was really terrible and it couldn't support T-mobile 4G LTE.
However, after I flash the recent PAC-MAN rom, it began supporting T-mobile 4G LTE.
The battery life is much better as well. Thanks to this rom, and my life is much easy now.
1. I do not know which one causes it begins supporting T-mobile LTE.
a. I made a mistake while factory reset at bootloader and I had to use my laptop to format the phone.
b. I installed the PAC-MAN rom after format.
Anyway, it's nice to support T-mobile LET since I just switch to them.
2. The battery life is much better. Before I can only use this phone for less than half day with the original battery.
Now, I can make few phone calls and play games for about half hr. The phone can last for more than 24 hrs.
3. The google voice/ MO+ is not working (either me or the one I call can't hear voice.) and the speaker mode is not working as well.
Anyway... I am very happy now..