So from a few reports on XDA, there’s some discussion on whether or not removing a piece of protective plastic from the back of the G2x results in better reception. The plastic can either be blue-ish or black like the picture above. It’s located right above the bottom speakers after you remove the back cover of the G2x. There’s no warranty voiding since it’s just a protective piece of plastic like you see on a lot of electronics.
One thing I did notice that was better was wifi calling. My first phone call out via wifi did not break up like it normally did. I’ll try on various access points through out the day, but try this out and see if it does anything for you.