I want phones using MediaTek SoCs in the US.

The specification I want.

SoC: MediaTek MT6752
RAM: 2GB or higher
ROM: 16GB or higher
Display Technology: IPS
Display Size: 5 inch ~ 5.5 inch
Display Resolution: 720p (HD)
Radio Bands: Supports both at&t and T-Mobile GSM, HSDPA+, and LTE bands
Battery Capacity: 2500 mAh or higher

I already own two MT6752 based phones. Their performance is satisfactory while their prices are very reasonable. The only drawback is both phones do not support some radio bands, especially LTE, at&t and T-Mobile use in the US.

Causes of "This device can perform faster" pop-up

We sometimes see the "This device can perform faster" pop-up message when we plug in a USB storage device to a computer. Why does it happen?
1. Wrong port
If you plug a USB 3.0 storage device into a USB 2.0 port, or USB 2.0 device into a USB 1.1 port, you will see the "This device can perform faster" message. This is not a big deal. The USB devices still work properly only with slower speed. If you want to enjoy the full speed, plug a USB 3.0 device into a USB 3.0 port. Same for a USB 2.0 device.

2. Wrong cable
If you use a USB 2.0 cable to connect a USB 3.0 device to a USB 3.0 port, you will see the "This device can perform faster" message. This is not a big deal either. Use a USB 3.0 cable for a USB 3.0 device and you will enjoy the full transfer speed of the USB 3.0 device.

3. Faulty device
This case is the worst case. This occurs mostly to USB 3.0 devices. The USB 3.0 connector has 5 additional pins which USB 2.0 and USB 1.1 connectors do not have. If any of the additional 5 pins of a USB 3.0 device malfunctions, the computer to which the USB 3.0 device is connect will assume the USB 3.0 device is connected to a USB 2.0 port even when the USB 3.0 device is in fact plugged into a USB 3.0 port. Hence, the computer shows you the annoying "This device can perform faster" message and limits the speed of the USB 3.0 device to the speed of the USB 2.0 protocol.

I have a 128 GB USB 3.0 flash drive. It used to work very well. It usually demonstrated 200 MB/s sequential read speed and 80 MB/s sequential write speed, which agrees well with the manufacturer's specs. However, one day, my computer showed me the "This device ... blah blah ..." message when I plugged the 128 GB USB 3.0 flash drive into a USB 3.0 port of the computer. I first thought I mistook a USB 2.0 port for a USB 3.0 port. But, the USB 3.0 flash drive was indeed plugged into a USB 3.0 port properly. Then, I thought the cause could be a wrong USB 3.0 driver. I uninstalled the old driver and installed a latest driver. But, I still saw the same "This device ..." message. Before trying another fix, I benchmarked the transfer speed of the USB 3.0 device with the "This device ..." message thinking it was not a huge issue as long as the transfer speed is correct. Unfortunately, the transfer speed decreased significantly. With the "This device..." message, the transfer speed of the USB 3.0 flash drive was only 40 MB/s for both sequential read and write. I still believed my computer was the reason. Thus, I tried the USB 3.0 flash drive on many other computers with USB 3.0 ports. The "This device ... " message popped up on all of the computers I tried and the transfer speed was also only 40 MB/s on all of the computers. Then, I concluded the USB 3.0 flash drive was the reason. I wanted to know what exactly was causing the issue. After examining the USB 3.0 flash drive quite thoroughly, I found out one of the 5 additional pins was broken. I am still using this USB 3.0 flash drive since it is still working except the transfer speed is less than half of its expected speed.

Best micro USB charger

Blackberry Folding Blade Charger for Playbook

http://www.amazon.com/Blackberry-Folding-Blade-Charger-Playbook/dp/B004OZMWUS

This charger is simply the best micro USB charger.

Affordable price
Reliable manufacturer
Huge output (1.8 A)
Long cable (6 feet long)

Buying a used mobile phone

When buying a used phone, buy only former flagship models.
I have concluded that buying used mid-range or budget phone is a waste of money.

My Wish for New Moto G

Moto G ver.2

8 GB or 16 GB internal storage
microSD slot (up to 64 GB)
LTE support (for both at&t and T-Mobile)
2400 mAh or larger battery size
The same physical dimensions
The sane display size
The same display resolution
Slightly better SoC than the first Moto G.
Factory Unlocked unit price $199.99

So, it's basically ATRIX HD with a larger battery size and a better exterior design.
Motorola can definitely do this.

T-Mobile APN, USA, LTE

Name:

T-Mobile USA LTE 

APN:

fast.t-mobile.com

MMSC: 

http://mms.msg.eng.t-mobile.com/mms/wapenc

MMS Proxy: 

Not set

MMS port: 

Not set

MCC: 

310

MNC: 

260

Authentication type: 

None

APN type: 

default,admin,fota,mms,supl,hipri,internet

APN protocol: 

IPv4/IPv6

APN roaming protocol:

IPv4/IPv6

MetroPCS LG Optimus F3 Android System Update

MetroPCS LG Optimus F3 Android System Update
Date: Dec 30 2013 (It could've been earlier since I kept my F3 off for a while)
Size: 111.8 MB

I seriously do not know what has changed.