Phone response slow, responds 2 - 10 seconds after touching screen or not at all, random lock ups, and power downs I have a non-rooted T-Mobile G2x by LG running Android 2.3.3. I have had it about two weeks and have noticed several problems.

Randomly shuts down. I go to use my phone and it doesn't come on, I press the power button and nothing happens, unless I long press which makes the phone boot. This has happened 3 or 4 times. The battery has a good state of charge, it's happened just sitting on my desk as well as when I wear it on my belt. It's also done this in the middle of a voice call.

Runs slow. I turn on the phone, the screen comes on, I swipe my unlock pattern, nothing happens for 2 - 10 seconds, then it shows me the pattern and unlocks the phone. It takes several attempts to unlock the phone because it doesn't always see the whole pattern. I swipe correctly the phone just doesn't pick it up.

The phone has locked up a couple of times, the screen is blank, playing with the power button does nothing. The only way I have been able to get the phone to come up is to remove and reinstall the battery.

The only thing I have noticed when it runs slow is I seem to be running out of ram. Less than 10%. If I kill the apps, it runs fast again, until the ram is gone which only takes 2 - 3 minutes before all of the apps using RAM have restarted.

Should I take the phone back to T-mobile and exchange it? If so any tips? I can just imagine the bureaucracy that I will have to deal with to get this accomplished.
Read an article at this location 
http://www.anandtech.com/show/4502/tmobile-g2x-review-gingerbread-infused/9

Seems to be a software problem.

Imho root and flash cyanogen or install the ROM after reading in XDA